Display device

ABSTRACT

A display device comprises a plurality of first banks disposed on a substrate to extend in a first direction and spaced apart from one another, a plurality of first patterns disposed between the plurality of first banks and spaced apart from one another in the first direction, a first electrode and a second electrode extending in the first direction and disposed on different first banks of the plurality of first banks and spaced apart from each other, a first insulating layer overlapping the plurality of first patterns, disposed on the first substrate, and to partially overlapping the first and second electrodes, and a plurality of light-emitting elements disposed on the first insulating layer so that first and second ends of each of the plurality of light-emitting elements are disposed on the first and second electrodes, respectively.

CROSS REFERENCE TO RELATED APPLICATION(S)

This application claims priority to and the benefit of Korean PatentApplication No. 10-2020-0049997 under 35 U.S.C. § 119, filed in theKorean Intellectual Property Office (KIPO) on Apr. 24, 2020, the entirecontents of which are incorporated herein by reference.

BACKGROUND 1. Technical Field

The disclosure relates to a display device.

2. Description of the Related Art

Display devices have become highly important with the development ofmultimedia, and various types of display devices, such as an organiclight-emitting diode (OLED) display device, a liquid crystal display(LCD) device, or the like, have been used.

A display device, which is a device for displaying an image, includes adisplay panel such as an OLED display panel or an LCD panel. The displaypanel may include light-emitting elements such as light-emitting diodes(LEDs), and the LEDs may be classified into OLEDs that use an organicmaterial as a fluorescent material and inorganic LEDs (ILEDs) that usean inorganic material as a fluorescent material.

SUMMARY

Embodiments of the disclosure provide a display device capable ofminimizing the number of light-emitting elements that are lost duringthe fabrication thereof.

Embodiments of the disclosure provide a display device with an improvedalignment of light-emitting elements on electrodes.

However, embodiments of the disclosure are not restricted to those setforth herein. The above and other embodiments of the disclosure willbecome more apparent to one of ordinary skill in the art to which thedisclosure pertains by referencing the detailed description of thedisclosure given below.

According to the aforementioned and other embodiments of the disclosure,a display device including a plurality of patterns, which are disposedbetween banks on which electrodes are arranged, is provided. Thepatterns are disposed to be spaced apart from one another in thedirection in which the electrodes and the banks extend and can thus formheight differences between the banks. The patterns, like the banks, canprovide space in which light-emitting elements are arranged, and thelight-emitting elements can be guided to be placed between the patterns,which are separate from one another, during the fabrication of thedisplay device.

Accordingly, the number of light-emitting elements that fail to beconnected to the electrodes and are lost because of being disposed inregions other than that between the banks can be minimized. Also, sincelight-emitting elements disposed between the patterns can have both endsthereof properly placed on the electrodes, the alignment of thelight-emitting elements can be improved.

Other features and embodiments may be apparent from the followingdetailed description, the drawings, and the claims.

According to an embodiment of the disclosure, a display device maycomprise a plurality of first banks disposed on a substrate to extend ina first direction and spaced apart from one another; a plurality offirst patterns disposed between the plurality of first banks and spacedapart from one another in the first direction; a first electrode and asecond electrode extending in the first direction, disposed on differentfirst banks of the plurality of first banks, and spaced apart from eachother; a first insulating layer overlapping the plurality of firstpatterns, disposed on the substrate, and partially overlapping the firstand second electrodes; and a plurality of light-emitting elementsdisposed on the first insulating layer so that first and second ends ofeach of the plurality of light-emitting elements are disposed on thefirst and second electrodes, respectively, the plurality oflight-emitting elements including first light-emitting elements whichare disposed between the plurality of first patterns not and do notoverlap the plurality of first patterns in a thickness direction of thedisplay device.

The plurality of light-emitting elements may further comprise secondlight-emitting elements which overlap the plurality of first patterns inthe thickness direction of the display device, and distances between thefirst light-emitting elements and the substrate may be smaller thandistances between the second light-emitting elements and the substrate.

A thickness of the plurality of first patterns may be greater thanthicknesses of the first and second electrodes.

The thickness of the plurality of first patterns may be smaller than adiameter of the plurality of light-emitting elements.

The plurality of first patterns may be disposed between the first andsecond electrodes, and a width of the plurality of first patterns may besmaller than a distance between the first and second electrodes.

A width of the plurality of first patterns may be greater than adistance between the first and second electrodes, and at least portionsof the first and second electrodes may be disposed on the plurality offirst patterns.

The display device may further comprise a planarization layer disposedon the substrate. The plurality of first banks and the first insulatinglayer may be disposed on the planarization layer, and the plurality offirst patterns and the planarization layer may be integral with eachother.

The plurality of first patterns may overlap portions of the first orsecond electrode that do not overlap the plurality of first banks and bearranged in the first direction.

First patterns of the plurality of first patterns that overlap the firstelectrode and first patterns of the plurality of first patterns thatoverlap the second electrode may be arranged parallel to a direction inwhich the first and second electrodes are spaced apart from each other.

First patterns of the plurality of first patterns that overlap the firstelectrode and first patterns of the plurality of first patterns thatoverlap the second electrode may be arranged in a staggered manner.

The display device may further comprise a first contact electrodedisposed on the first electrode to be in electrical contact with firstends of the plurality of light-emitting elements and a second contactelectrode disposed on the second electrode to be in electrical contactwith second ends of the plurality of light-emitting elements.

The first electrode may include at least one bent portion which extendsin a second direction that is different from the first direction, anextended portion which has a greater width than the at least one bentportion, and at least one connecting portion which electrically connectsthe bent portions and the extended portion and extends in the firstdirection, and the plurality of first patterns may be disposed betweenthe extended portion of the first electrode and the second electrode.

The second electrode may be symmetrical with the first electrode withrespect to the first insulating layer, the plurality of first patternsmay be disposed between the extended portion of the first electrode andan extended portion of the second electrode, and a first end and asecond end of each of the plurality of light-emitting elements may bedisposed on the extended portions of the first and second electrodes,respectively.

A first distance between the extended portion of the first electrode andthe second electrode may be smaller than a second distance between theat least one connecting portion of the first electrode and the secondelectrode, and a minimum distance between the at least one bent portionof the first electrode and the second electrode may be greater than thefirst distance and is smaller than the second distance.

According to an embodiment of the disclosure, a display device maycomprise a planarization layer disposed on the substrate; a plurality offirst banks disposed on the planarization layer and spaced apart fromone another; a first electrode and a second electrode disposed ondifferent first banks of the plurality of first banks and spaced apartfrom each other; a first insulating layer disposed on the planarizationlayer and partially overlapping the first and second electrodes; firstlight-emitting elements disposed on the first insulating layer so that afirst end and a second end of each of the first light-emitting elementsare disposed on the first electrode and the second electrode,respectively; and second light-emitting elements disposed on the firstinsulating layer so that a first end and a second end of each of thesecond light-emitting elements are disposed on the first electrode andthe second electrode, respectively, wherein a distance between the firstlight-emitting elements and the substrate is smaller than a distancebetween the second light-emitting elements and the substrate.

The planarization layer may include first patterns including topsurfaces partially protruding between the plurality of first banks, andthe second light-emitting elements may be disposed on the firstpatterns.

The planarization layer may include portions between the plurality offirst banks where the first patterns are not formed, and the firstlight-emitting elements may be disposed on the portions of theplanarization layer where the first patterns are not formed.

The planarization layer may include recesses between the plurality offirst banks. A top surface of the planarization layer may be recessed,at least portions of the first and second electrodes may be disposed inthe recesses, and the first light-emitting elements may be disposed inthe recesses.

The planarization layer may include portions between the plurality offirst banks where the recesses are not formed, and the secondlight-emitting elements may be disposed on the portions of theplanarization layer where the recesses are not formed.

The display device may further comprise a transistor disposed betweenthe substrate and the planarization layer; and a data conductive layerdisposed between the transistor and the planarization layer andincluding a first voltage line and second voltage line, wherein thefirst electrode may be electrically connected to the first voltage linevia the transistor, and the second electrode may be electricallyconnected to the second voltage line.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects will become apparent and more readilyappreciated from the following description of the embodiments, taken inconjunction with the accompanying drawings in which:

FIG. 1 is a schematic plan view of a display device according to anembodiment of the disclosure;

FIG. 2 is a schematic plan view of a pixel of the display device of FIG.1;

FIG. 3 is a schematic cross-sectional view taken along lines Q1-Q1′,Q2-Q2′, and Q3-Q3′ of FIG. 2;

FIG. 4 is a schematic cross-sectional view taken along line Q4-Q4′ ofFIG. 2;

FIG. 5 is a schematic cross-sectional view taken along line Q5-Q5′ ofFIG. 2;

FIG. 6 is a schematic enlarged cross-sectional view of portion QA ofFIG. 4;

FIG. 7 is a schematic cross-sectional view taken along line Q6-Q6′ ofFIG. 2;

FIG. 8 is a schematic partial cross-sectional view of a display deviceaccording to another embodiment of the disclosure;

FIG. 9 is a schematic perspective view of a light-emitting elementaccording to an embodiment of the disclosure;

FIGS. 10 through 12 are schematic cross-sectional views illustratingprocesses of a method of fabricating a display device according to anembodiment of the disclosure;

FIG. 13 is a schematic plan view of a subpixel obtained by the processesillustrated in FIG. 12;

FIGS. 14 and 15 are schematic cross-sectional views illustratingprocesses of the method of fabricating a display device according to anembodiment of the disclosure;

FIG. 16 is a schematic plan view of a subpixel obtained by the processesillustrated in FIGS. 14 and 15;

FIGS. 17 through 19 are schematic cross-sectional views illustrating thearrangement of light-emitting elements and first patterns in thesubpixel of FIG. 16;

FIGS. 20 and 21 are schematic cross-sectional views illustratingprocesses of the method of fabricating a display device according to anembodiment of the disclosure;

FIGS. 22 through 24 are schematic partial cross-sectional views ofdisplay devices according to other embodiments of the disclosure;

FIGS. 25 and 26 are schematic partial cross-sectional views of displaydevices according to other embodiments of the disclosure;

FIG. 27 is a schematic partial cross-sectional view of a display deviceaccording to another embodiment of the disclosure;

FIG. 28 is a schematic plan view of a subpixel of the display device ofFIG. 27;

FIG. 29 is a schematic plan view of a subpixel of a display deviceaccording to another embodiment of the disclosure;

FIG. 30 is a schematic cross-sectional view taken along line QB-QB′ ofFIG. 29;

FIG. 31 is a schematic plan view of a subpixel of a display deviceaccording to another embodiment of the disclosure;

FIG. 32 is a schematic cross-sectional view taken along lines QC-QC′,QD-QD′, and QE-QE′ of FIG. 31;

FIG. 33 is a schematic plan view of a subpixel of a display deviceaccording to another embodiment of the disclosure;

FIG. 34 is a schematic plan view of a subpixel of a display deviceaccording to another embodiment of the disclosure; and

FIG. 35 is a schematic cross-sectional view taken along line QX-QX′ ofFIG. 34.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The disclosure will now be described more fully hereinafter withreference to the accompanying drawings, in which preferred embodimentsof the disclosure are shown. This disclosure may, however, be embodiedin different forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will convey thescope of the disclosure to those skilled in the art.

It will also be understood that when a layer is referred to as being“on” another layer or substrate, it can be directly on the other layeror substrate, or one or more intervening layers may also be present. Thesame reference numerals indicate the same components throughout thespecification.

It will be understood that although the terms “first,” “second,” or thelike may be used herein to describe various elements, these elementsshould not be limited by these terms. These terms are only used todistinguish one element from another element. For instance, a firstelement discussed below could be termed a second element withoutdeparting from the teachings of the disclosure. Similarly, the secondelement could also be termed the first element.

Unless otherwise defined or implied herein, all terms (includingtechnical and scientific terms) used have the same meaning as commonlyunderstood by those skilled in the art to which this disclosurepertains. It will be further understood that terms, such as thosedefined in commonly used dictionaries, should be interpreted as having ameaning that is consistent with their meaning in the context of therelevant art and should not be interpreted in an ideal or excessivelyformal sense unless clearly defined in the specification.

Hereinafter, embodiments will be described with reference to theaccompanying drawings.

FIG. 1 is a schematic plan view of a display device according to anembodiment of the disclosure.

The terms “above,” “top,” and “on,” as used herein, refer to an upwarddirection from a display device 10, i.e., one direction of a thirddirection DR3, and the terms “below,” “bottom,” and “under,” as usedherein, refer to a downward direction from the display device 10, i.e.,the other direction of the third direction DR3. The terms “left,”“right,” “upper,” and “lower,” as used herein, refer to their respectivedirections as viewed from above the display device 10. For example, theterms ““left,” “right,” “upper,” and “lower” refer to one direction of afirst direction DR1, the other direction of the first direction DR1, onedirection of a second direction DR2, and the other direction of thesecond direction DR2, respectively.

Referring to FIG. 1, a display device 10 displays a moving or stillimage. The display device 10 may refer to nearly all types of electronicdevices that include a display screen. Examples of the display device 10may include a television (TV), a notebook computer, a monitor, abillboard, an Internet-of-Things (IoT) device, a mobile phone, asmartphone, a tablet personal computer (PC), an electronic watch, asmartwatch, a watchphone, a head-mounted display, a mobile communicationterminal, an electronic notepad, an electronic book, a portablemultimedia player (PMP), a navigation device, a gaming console, adigital camera, and a camcorder.

The display device 10 may include a display panel that includes adisplay screen. Examples of the display panel include an inorganiclight-emitting diode (ILED) display panel, an organic LED (OLED) displaypanel, a quantum-dot light-emitting diode (QLED) display panel, a plasmadisplay panel (PDP), and a field emission display (FED) panel. Thedisplay panel of the display device 10 will hereinafter be described asbeing an ILED display panel, but the disclosure is not limited thereto.

The shape of the display device 10 may vary. For example, the displaydevice 10 may have a rectangular shape that extends longer in ahorizontal direction than in a vertical direction, a rectangular shapethat extends longer in the vertical direction than in the horizontaldirection, a square shape, a rectangular shape with rounded corners,another polygonal shape, or a circular shape. A display area DPA of thedisplay device 10 may have a similar shape to the display device 10.FIG. 1 illustrates that the display device 10 and the display area DPAhave a rectangular shape that extends longer in the horizontal directionthan in the vertical direction.

The display device 10 may include the display area DPA and a non-displayarea NDA. The display area DPA is an area in which an image isdisplayed, and the non-display area NDA is an area in which an image isnot displayed. The display area DPA may also be referred to as an activearea, and the non-display area NDA may also be referred to as aninactive area. The display area DPA may generally account for a middleportion of the display device 10.

The display area DPA may include pixels PX. The pixels PX may bearranged in row and column directions. The pixels PX may have arectangular or square shape in a plan view, but the disclosure is notlimited thereto. As another example, the pixels PX may have a rhombusshape that is inclined with respect to the first or second direction. Asanother example, the pixels PX may be arranged in a stripe fashion or aPenTile® fashion. Each of the pixels PX may include one or morelight-emitting elements 30 that emit light of a predetermined wavelengthrange to emit light of a predetermined color.

The non-display area NDA may be disposed on the periphery of the displayarea DPA. The non-display area NDA may surround the entire display areaDPA or a portion of the display area DPA. The display area DPA may havea rectangular shape, and the non-display area NDA may be disposedadjacent to four sides of the display area DPA. The non-display area NDAmay form a bezel of the display device 10. Wires or circuit driversincluded in the display device 10 may be disposed in the non-displayarea NDA, or external devices may be mounted in the non-display areaNDA.

FIG. 2 is a schematic plan view of a pixel of the display device of FIG.1.

Referring to FIG. 2, a pixel PX may include subpixels PXn (where n is aninteger of 1 to 3). For example, the pixel PX may include first, second,and third subpixels PX1, PX2, and PX3. The first subpixel PX1 may emitlight of a first color, the second subpixel PX2 may emit light of asecond color, and the third subpixel PX3 may emit light of a thirdcolor. The first, second, and third colors may be blue, green, and red,respectively, but the disclosure is not limited thereto. As anotherexample, the subpixels PXn may emit light of the same color. FIG. 2illustrates that the pixel PX includes three subpixels PXn, but thedisclosure is not limited thereto. As another example, the pixel PX mayinclude more than three subpixels PXn.

Each of the subpixels PXn may include an emission area EMA and anon-emission area. The emission area EMA may be an area in which one ormore light-emitting elements 30 are disposed to emit light of aparticular wavelength range, and the non-emission area may be an areathat light emitted from the light-emitting elements 30 does not extendto and no light is thus emitted from. The emission area EMA may includean area in which the light-emitting elements 30 are disposed, and anarea that outputs light emitted from the light-emitting elements 30.

However, the disclosure is not limited to this. The emission area EMAmay further include an area in which light emitted from thelight-emitting elements 30 is reflected or refracted by another element.Light-emitting elements 30 may be disposed in the subpixels PXn andemission areas EMA, including areas where the light-emitting elements 30are disposed and areas adjacent to the areas where the light-emittingelements 30 are disposed, may be formed.

Each of the subpixels PXn may include a cut area CBA, which is disposedin the non-emission area. The cut area CBA may be disposed on one side,in the second direction DR2, of the emission area EMA. The cut area CBAmay be disposed between emission areas EMA of a pair of adjacentsubpixels PXn in the second direction DR2. In the display area DPA ofthe display device 10, emission areas EMA and cut areas CBA may bearranged. For example, the emission areas EMA or the cut areas CBA maybe arranged one after another in the first direction DR1, and theemission areas EMA or the cut areas CBA may be alternately arranged inthe second direction DR2. The distance, in the first direction DR1,between the cut areas CBA may be smaller than the distance, in the firstdirection DR1, between the emission areas EMA. A second bank 45 may bedisposed between the cut areas CBA and the emission areas EMA, and thedistance between the cut areas CBA and the emission areas EMA may bedetermined by the width of the second bank 45. No light-emittingelements 30 are disposed in the cut areas CBA so that no light isemitted from the cut areas CBA, but portions of electrodes 21 and 22disposed in each of the subpixels PXn may be disposed in thecorresponding cut area CBA to be separated from each other.

FIG. 3 is a schematic cross-sectional view taken along lines Q1-Q1′,Q2-Q2′, and Q3-Q3′of FIG. 2. FIG. 4 is a schematic cross-sectional viewtaken along line Q4-Q4′ of FIG. 2. FIG. 5 is a schematic cross-sectionalview taken along line Q5-Q5′ of FIG. 2. Specifically, FIG. 3 illustratesa schematic cross-sectional view of the first subpixel PX1 of FIG. 2,but the structure of the first subpixel PX1 illustrated in FIG. 3 may bedirectly applicable to other pixels PX or other subpixels PXn. FIG. 3illustrates a schematic cross-sectional view taken along the firstdirection DR1 of first light-emitting elements 30A and secondlight-emitting elements 30B of the first subpixel PX1. FIG. 4illustrates a schematic cross-sectional view of first patterns 70 of thefirst subpixel PX1 with no light-emitting elements 30 disposed thereon,and FIG. 5 illustrates a schematic cross-sectional view of firstpatterns 70 of the first subpixel PX1 with light-emitting elements 30disposed thereon.

Referring to FIGS. 3 through 5 and further to FIG. 2, the display device10 may include a first substrate 11 and a semiconductor layer,conductive layers, and insulating layers, which are disposed on thefirst substrate 11.

The first substrate 11 may be an insulating substrate. The firstsubstrate 11 may be formed of an insulating material such as glass,quartz, or a polymer resin. Also, the first substrate 11 may be a rigidsubstrate but may be a flexible substrate that is bendable, foldable, orrollable.

A light-blocking layer BIL may be disposed on the first substrate 11.The light-blocking layer BIL is disposed to overlap an active layer ACTof a first transistor TR1. The light-blocking layer BIL may include amaterial capable of blocking light and may prevent light from beingincident upon the active layer ACT of the first transistor TR1. Forexample, the light-blocking layer BIL may be formed of an opaque metalcapable of blocking the transmission of light, but the disclosure is notlimited thereto. In some embodiments, the light-blocking layer BMIL maynot be provided.

A buffer layer 12 may be disposed on the entire surface of the firstsubstrate 11 including the light-blocking layer BML. The buffer layer 12may be formed on the first substrate 11 to protect the first transistorTR1, which is susceptible to moisture, from moisture that may penetratethe first substrate 11 and may perform a surface planarization function.The buffer layer 12 may include inorganic layers that are alternatelystacked. For example, the buffer layer 12 may be formed as a multilayerfilm in which inorganic layers including at least one of silicon oxide(SiO_(x)), silicon nitride (SiN_(x)), and silicon oxynitride (SiON) arealternately stacked.

The semiconductor layer is disposed on the buffer layer 12. Thesemiconductor layer may include the active layer ACT of the firsttransistor TR1. The semiconductor layer may be disposed to partiallyoverlap a gate electrode GE in a first gate conductive layer.

FIG. 3 illustrates only the first transistor TR1 of the first subpixelPX1, but the number of transistors included in the first subpixel PX1 isnot particularly limited. The first subpixel PX1 may include more thanone transistor. For example, the first subpixel PX1 may include morethan one transistor including the first transistor TR1, for example, twoor three transistors.

The semiconductor layer may include polycrystalline silicon,monocrystalline silicon, or an oxide semiconductor. In a case where thesemiconductor layer includes an oxide semiconductor, the active layerACT may include conductor regions (ACT_a and ACT_b) and a channel regionACT_c between the conductor regions (ACT_a and ACT_b). The oxidesemiconductor may be an oxide semiconductor including indium (In). Insome embodiments, the oxide semiconductor may be indium tin oxide (ITO),indium zinc oxide (IZO), indium gallium oxide (IGO), indium zinc tinoxide (IZTO), indium gallium tin oxide (IGTO), indium gallium zinc oxide(IGZO), or indium gallium zinc tin oxide (IGZTO), but the disclosure isnot limited thereto.

As another example, the semiconductor layer may include polycrystalline,which is formed by crystallizing amorphous silicon. In this case, theconductor regions (ACT_a and ACT_b) of the active layer ACT may beregions doped with impurities.

A first gate insulating layer 13 is disposed on the semiconductor layerand the buffer layer 12. The first gate insulating layer 13 may includea semiconductor layer and may be disposed on the buffer layer 12. Thefirst gate insulating layer 13 may function as the gate insulating filmof each of transistors. The first gate insulating layer 13 may be formedas an inorganic layer including an inorganic material such as, forexample, SiO_(x), SiN_(x), or SiON or as a stack of SiO_(x), SiN_(x),and/or SiON.

The first gate conductive layer is disposed on the first gate insulatinglayer 13. The first gate conductive layer may include the gate electrodeGE of the first transistor TR1 and a first capacitor electrode CSE of astorage capacitor. The gate electrode GE may be disposed to overlap thechannel region ACT_c of the active layer ACT in a thickness direction.The first capacitor electrode CSE may be disposed to overlap a firstsource/drain electrode SD1 of the first transistor TR1 in the thicknessdirection. In some embodiments, the first capacitor electrode CSE may beconnected to, and be integrated into a single layer with, the gateelectrode GE, and the single layer may include, in part, the gateelectrode GE and the first capacitor electrode CSE. The first capacitorelectrode CSE may be disposed to overlap the first source/drainelectrode SD1 in the thickness direction so that the storage capacitormay be formed between the first capacitor electrode CSE and the firstsource/drain electrode SD1.

The first gate conductive layer may be formed as a single- or multilayerfilm including molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au),titanium (Ti), nickel (Ni), neodymium (Nd), copper (Cu), or an alloythereof, but the disclosure is not limited thereto.

A first passivation layer 15 is disposed on the first gate conductivelayer. The first passivation layer 15 may cover or overlap the firstgate conductive layer to protect the first gate conductive layer. Thefirst passivation layer 15 may be formed as an inorganic layer includingan inorganic material such as, for example, SiO_(x), SiN_(x), or SiON oras a stack of SiO_(x), SiN_(x), and/or SiON.

A first data conductive layer is disposed on the first passivation layer15. The first data conductive layer may include the first source/drainelectrode SD1, a second source/drain electrode SD2, and a data line DTL.

Source/drain electrodes (SD1 and SD2) of the first transistor TR1 may bein electrical contact with the conductor regions (ACT_a and ACT_b) ofthe active layer ACT via contact holes that penetrate the firstinterlayer insulating layer 17 and the first gate insulating layer 13.The second source/drain electrode SD2 of the first transistor TR1 may beelectrically connected to the light-blocking layer BML via anothercontact hole.

The data line DTL may apply a data signal to other transistors (notillustrated) of the first subpixel PX1. Although not specificallyillustrated, the data line DTL may be electrically connected to thesource/drain electrodes of the other transistors and may transmit thedata signal to the source/drain electrodes of the other transistors.

The first data conductive layer may be formed as a single- ormulti-layer film including Mo, Al, Cr, Au, Ti, Ni, Nd, Cu, or an alloythereof, but the disclosure is not limited thereto.

The first interlayer insulating layer 17 is disposed on the first dataconductive layer. The first interlayer insulating layer 17 may functionas an insulating film between the first data conductive layer and layersdisposed on the first data conductive layer. Also, the first interlayerinsulating layer 17 may cover or overlap the first data conductive layerto protect the first data conductive layer. The first interlayerinsulating layer 17 may be formed as an inorganic layer including aninorganic material such as, for example, SiO_(x), SiN_(x), or SiON or asa stack of SiO_(x), SiN_(x), and/or SiON.

A second data conductive layer is disposed on the first interlayerinsulating layer 17. The second data conductive layer may include afirst voltage line VL1, a second voltage line VL2, and a firstconductive pattern CDP. A high-potential voltage (or the first powersupply voltage) provided to the first transistor TR1 may be applied tothe first voltage line VL1, and a low-potential voltage (or the secondpower supply voltage) provided to a second electrode 22 may be appliedto the second voltage line VL2. Alight-emitting element alignment signalfor aligning light-emitting elements 30 may also be applied to thesecond voltage line VL2 during the fabrication of the display device 10.

The first conductive pattern CDP may be electrically connected to thesecond source/drain electrode SD2 of the first transistor TR1 via acontact hole formed in the first interlayer insulating layer 17. Thefirst conductive pattern CDP may be in electrical contact with a firstelectrode 21 that will be described below. The first transistor TR1 maytransmit the first power supply voltage, applied from the first voltageline VL1, to the first electrode 21 via the first conductive patternCDP. The second data conductive layer is illustrated as including onefirst voltage line VL1 and one second voltage line VL2, but thedisclosure is not limited thereto. As another example, the second dataconductive layer may include more than one first voltage line VL1 andmore than one second voltage line VL2.

The second data conductive layer may be formed as a single- ormulti-layer film including Mo, Al, Cr, Au, Ti, Ni, Nd, Cu, or an alloythereof, but the disclosure is not limited thereto.

A first planarization layer 19 is disposed on the second data conductivelayer. The first planarization layer 19 may include an organicinsulating material such as, for example, polyimide (PI), and mayperform a surface planarization function.

First banks 40, first patterns 70, electrodes (21 and 22),light-emitting elements 30, a second bank 45, and contact electrodes (26and 27) may be disposed on the first planarization layer 19. Insulatinglayers (51, 52, 53, and 54) may be further disposed on the firstplanarization layer 19.

The first banks 40 may be disposed directly on the first planarizationlayer 19. The first banks 40 may extend in the second direction DR2within the first subpixel PX1; may not extend into neighboring subpixelsPXn, in the second direction DR2, of the first subpixel PX1; and may bedisposed in an emission area EMA of the first subpixel PX1. The firstbanks 40 may be disposed to be spaced apart from one another in thefirst direction DR1 and may form a region where the light-emittingelements 30 are to be disposed. The first banks 40 may be disposed ineach subpixel PXn to form linear patterns in the display area DPA of thedisplay device 10. Two first banks 40 are illustrated as being providedin the first subpixel PX1, but the disclosure is not limited thereto.More than two first banks 40 may be disposed in the first subpixeldepending on the number of electrodes (21 and 22) that will be describedbelow.

The first banks 40 may protrude, at least in part, from the top surfaceof the first planarization layer 19. Portions of the first banks 40 thatprotrude may have inclined sides surfaces, and light emitted from thelight-emitting elements 30 may travel toward the inclined side surfaces.The electrodes (21 and 22), which are disposed on the first banks 40,may include a material with high reflectance, and light emitted from thelight-emitting elements 30 may be reflected to be emitted in an upwarddirection from the first planarization layer 19. For example, the firstbanks 40 may not only provide an area in which to arrange thelight-emitting elements 30, but also may function as a reflectingbarrier capable of reflecting light emitted from the light-emittingelements 30 in the upward direction from the first planarization layer19. The sides of the first banks 40 may be linearly inclined, but thedisclosure is not limited thereto. As another example, the first banks40 may have a semi-circular or elliptical shape with a curved outersurface. The first banks 40 may include an organic insulating materialsuch as PI, but the disclosure is not limited thereto.

The display device 10 may include first patterns 70, which are disposedbetween the first banks 40. The first patterns 70 may have a smallerwidth than the first banks 40 and may be disposed to be spaced apartfrom one another in the second direction DR2, between the first banks40. The width of the first patterns 70 may be smaller than the distancebetween the first banks 40, and the first patterns 70 may be spacedapart from the first banks 40. In some embodiments, the first patterns70 and the first banks 40 may include the same material and may beformed at the same time.

As already mentioned above, the first banks 40 may form the region wherethe light-emitting elements 30 are to be disposed. During thefabrication of the display device 10, ink having the light-emittingelements 30 scattered therein may be sprayed on the electrodes (21 and22), and the light-emitting elements 30 may be arranged on theelectrodes (21 and 22) by an electric field generated on the electrodes(21 and 22). Here, the first banks 40 may protrude from the top surfaceof the first planarization layer 19 to define a region therebetween anda region on the outside thereof and may guide the light-emittingelements 30 to be placed between the first banks 40. Similarly, thefirst patterns 70, which are disposed between the first banks 40, maygenerate height differences in the region between the first banks 40where the light-emitting elements 30 are disposed. Thus, regions wherethe first patterns 70 are disposed may be differentiated from regionsbetween the first patterns 70 spaced apart from one another in thesecond direction DR2, and the light-emitting elements 30 may be guidedto be placed between the first patterns 70. As a result, thelight-emitting elements 30 can be densely arranged in a particular areabetween the first banks 40, and both ends of each of the light-emittingelements 30 can be properly arranged on the electrodes (21 and 22). Thefirst patterns 70 will be described below in detail.

Electrodes (21 and 22) are disposed on the first bank 40 and the firstplanarization layer 19. The electrodes (21 and 22) may include the firstand second electrodes 21 and 22. The first and second electrodes 21 and22 may extend in the second direction DR2 and may be spaced apart fromeach other in the first direction DR1.

The first and second electrodes 21 and 22 may extend in the seconddirection DR2 in each subpixel PXn and may be separated from otherelectrodes (21 and 22) by the cut area CBA of the corresponding subpixelPXn. In some embodiments, a cut area CBA may be disposed between theemission areas EMA of two adjacent subpixels PXn in the second directionDR2, and first and second electrodes 21 and 22 of one of the twoadjacent subpixels PXn may be separated from first and second electrodes21 and 22 of the other subpixel PXn, but the disclosure is not limitedthereto. As another example, some electrodes (21 and 22) may not besegmented between subpixels PXn, but may extend across the boundarybetween each pair of adjacent subpixels PXn in the second direction DR2,or only one of the first and second electrodes 21 and 22 may besegmented between the subpixels PXn.

The first electrode 21 may be electrically connected to the firsttransistor TR1 via a first contact hole CT1, and the second electrode 22may be electrically connected to the second voltage line VL2 via asecond contact hole CT2. For example, the first electrode 21 may be inelectrical contact with the first conductive pattern CDP via the firstcontact hole CT1, which penetrates the first planarization layer 19 inan area where the second bank 45 extends in the first direction DR1, andthe second electrode 22 may be in electrical contact with the secondvoltage line VL2 via a second contact hole CT2, which penetrates thefirst planarization layer 19 in the area where the second bank 45extends in the first direction DR1. However, the disclosure is notlimited to this example. In another example, the first and secondcontact holes CT1 and CT2 may be disposed in the emission area EMAsurrounded by the second bank 45 not to overlap the second bank 45.

One first electrode 21 and one second electrode 22 are illustrated asbeing provided in each subpixel PXn, but the disclosure is not limitedthereto. More than one first electrode 21 and more than one secondelectrode 22 may be provided in each subpixel PXn. Also, in eachsubpixel PXn, the first and second electrodes 21 and 22 may notnecessarily extend in one direction but may be arranged in various otherfashions. For example, the first and second electrodes 21 and 22 may bepartially curved or bent, or one of the first and second electrodes 21and 22 may be disposed to surround the other electrode.

The first and second electrodes 21 and 22 may be disposed on theirrespective first banks 40. In some embodiments, the first and secondelectrodes 21 and 22 may be formed to have a greater width than thefirst banks 40. For example, the first and second electrodes 21 and 22may be formed to cover the outer surfaces of their respective firstbanks 40. The first and second electrodes 22 may be disposed on thesides of their respective first banks 40, and the distance between thefirst and second electrodes 21 and 22 may be smaller than the distancebetween the first banks 40. The first and second electrodes 21 and 22may be disposed, at least in part, directly on the first planarizationlayer 19 and may thus be on the same plane.

The electrodes (21 and 22) may include a conductive material with highreflectance. For example, the electrodes (21 and 22) may include a metalwith high reflectance such as Ag, Cu, or Al or may include an alloy ofAl, Ni, or La. The electrodes (21 and 22) may reflect light emitted fromthe light-emitting elements 30 to travel toward the sides of the firstbanks 40 in an upward direction from each subpixel PXn.

However, the disclosure is not limited to this, and the electrodes (21and 22) may further include a transparent conductive material. Forexample, the electrodes (21 and 22) may include a material such as ITO,IZO, or ITZO. In some embodiments, each of the electrodes (21 and 22)may form a structure in which a transparent conductive material and ametal with high reflectance are stacked into more than one layer, or maybe formed as a single layer including a transparent conductive materialand a metal with high reflectance. For example, each of the electrodes(21 and 22) may have a stack of ITO/Ag/ITO, ITO, ITO/Ag/IZO, orITO/Ag/ITZO/IZO.

The electrodes (21 and 22) may be electrically connected to thelight-emitting elements 30, and a predetermined voltage may be appliedto each of the electrodes (21 and 22) so that the light-emittingelements 30 can emit light. For example, the electrodes (21 and 22) maybe electrically connected to the light-emitting elements 30 via thecontact electrodes (26 and 27) that will be described below, and maytransmit electrical signals applied thereto to the light-emittingelements 30 via the contact electrodes (26 and 27).

One of the first and second electrodes 21 and 22 may be electricallyconnected to anode electrodes of the light-emitting elements 30, and theother electrode of the first and second electrodes 21 and 22 may beelectrically connected to cathode electrodes of the light-emittingelements 30. However, the disclosure is not limited to this. As anotherexample, one of the first and second electrodes 21 and 22 may beelectrically connected to the cathode electrodes of the light-emittingelements 30, and the other electrode of the first and second electrodes21 and 22 may be electrically connected to the anode electrodes of thelight-emitting elements 30.

The electrodes (21 and 22) may be used to generate an electric field ineach subpixel PXn to align the light-emitting elements 30. Thelight-emitting elements 30 may be arranged between the first and secondelectrodes 21 and 22 by the electric field formed on the first andsecond electrodes 21 and 22. The light-emitting elements 30 may besprayed on the electrodes (21 and 22) via inkjet printing. If inkincluding the light-emitting elements 30 is sprayed on the electrodes(21 and 22), alignment signals may be applied to the electrodes (21 and22) to generate an electric field. The light-emitting elements 30scattered in the ink may receive a dielectrophoretic force from theelectric field generated on the electrodes (21 and 22) and may thus beproperly aligned on the electrodes (21 and 22).

A first insulating layer 51 is disposed on the first planarization layer19. The first insulating layer 51 may be disposed to cover the firstbanks 40, the first and second electrodes 21 and 22, and the firstpatterns 70, over the first planarization layer 19, but to exposeportions of the top surfaces of the first and second electrodes 21 and22. In other words, the first insulating layer 51 may be formedsubstantially on the entire surface of the first planarization layer 19and may include openings (not illustrated) that expose portions of thefirst and second electrodes 21 and 22.

For example, portions of the top surface of the first insulating layer51 may be recessed between the first and second electrodes 21 and 22 togenerate height differences. As the first insulating layer 51 isdisposed to cover or overlap the first patterns 70 between the firstbanks 40, height differences may be generated in portions of the topsurface of the first insulating layer 51 along the direction in whichthe first patterns 70 are arranged, i.e., along the second directionDR2. As the first insulating layer 51 is disposed to cover the first andsecond electrodes 21 and 22, even in the regions where the firstpatterns 70 are not disposed, height differences may be generated evenin portions of the top surface of the first insulating layer 51 betweenthe first and second electrodes 21 and 22. However, the disclosure isnot limited to this.

The first insulating layer 51 may protect the first and secondelectrodes 21 and 22 and may insulate the first and second electrodes 21and 22 from each other. Also, the first insulating layer 51 may preventthe light-emitting elements 30, which are disposed on the firstinsulating layer 51, from being in direct contact with, and damaged by,other elements.

The second bank 45 may be disposed on the first insulating layer 51. Ina plan view, the second bank 45 may include portions that extend in thefirst direction DR1 and portions that extend in the second direction DR2and may be arranged in a lattice pattern on the entire surface of thedisplay area DPA. The second bank 45 may be disposed along theboundaries of each subpixel PXn to define each subpixel PXn.

The second bank 45 may be disposed to surround the emission area EMA andthe cut area CBA of each subpixel PXn to separate the emission area EMAand the cut area CBA of each subpixel PXn. The first and secondelectrodes 21 and 22 may extend in the second direction DR2 across theportions of the second bank 45 that extend in the first direction DR1.The portions of the second bank 45 that extend in the second directionDR2 may have a greater width between emission areas EMA of each pair ofadjacent subpixels PXn than between cut areas CBA of each pair ofadjacent subpixels PXn. Accordingly, the distance between the cut areasCBA may be smaller than the distance between the emission areas EMA.

The second bank 45 may be formed to have a greater height than the firstbanks 40. The second bank 45 may prevent ink from spilling over betweendifferent subpixels PXn during an inkjet printing process during thefabrication of the display device 10. The second bank 45 may separateink having the light-emitting elements 30 scattered therein betweendifferent subpixels PXn and may prevent mixture of the ink. The secondbank 45, like the first banks 40, may include polyimide (PI), but thedisclosure is not limited thereto.

The light-emitting elements 30 may be disposed on the first insulatinglayer 51. Light-emitting elements 30 may be disposed to be spaced apartfrom one another in the direction in which the electrodes (21 and 22)extend, i.e., in the second direction DR2, and may be alignedsubstantially in parallel to one another. The distance between thelight-emitting elements 30 is not particularly limited. Thelight-emitting elements 30 may extend in one direction, and thedirection in which the electrodes (21 and 22) extend may form asubstantially right angle with the direction in which the light-emittingelements 30 extend. However, the disclosure is not limited to this. Asanother example, the light-emitting elements 30 may be arrangeddiagonally with respect to the direction in which the electrodes (21 and22) extend.

The light-emitting elements 30 may include light-emitting layers 36having different materials and may emit light of different wavelengthranges to the outside. The display device 10 may include light-emittingelements 30 that emit light of different wavelength ranges. Accordingly,the first, second, and third subpixels PX1, PX2, and PX3 can emit lightof the first, second, and third colors, respectively, but the disclosureis not limited thereto. As another example, the subpixels PXn mayinclude light-emitting elements 30 of the same type and may emit lightof substantially the same color.

The light-emitting element 30 may be arranged between the first banks 40so that both ends thereof may be placed on the electrodes (21 and 22).For example, first ends of the light-emitting elements 30 may bedisposed on the first electrode 21, and second ends of thelight-emitting elements 30 may be disposed on the second electrode 22.The length of the light-emitting elements 30 may be greater than thedistance between the first and second electrodes 21 and 22, and bothends of each of the light-emitting elements 30 may be disposed on thefirst and second electrodes 22.

The light-emitting elements 30 may be disposed between the firstpatterns 70 or on the first patterns 70. For example, the light-emittingelements 30 may include first light-emitting elements 30A, which aredisposed in the regions where the first patterns 70 are not disposed,and second light-emitting elements 30B, which are disposed on the firstpatterns 70. The first insulating layer 51 may be disposed between thefirst banks 40 and between the first and second electrodes 21 and 22 tocover the first patterns 70. The light-emitting elements 30, which aredisposed on the first insulating layer 51, may be disposed on portionsof the first insulating layer 51 that are relatively low between thefirst patterns 70, and at least some of the light-emitting elements 30may be disposed to overlap the first patterns 70 in the thicknessdirection. FIG. 3 illustrates a schematic cross-sectional view takenfrom one end to the other end of one of the first light-emittingelements 30A, and FIG. 4 illustrates a schematic cross-sectional viewtaken from one end to the other end of one of the second light-emittingelements 30B. For example, the first patterns 70 may be disposed betweenthe first banks 40 to generate height differences in the firstinsulating layer 51, and the light-emitting elements 30 may includefirst light-emitting elements 30A that are located relatively low andsecond light-emitting elements 30B that are located relatively high. Asthe first patterns 70 are provided, most of the light-emitting elements30 may be the first light-emitting elements 30A, which are locatedrelatively low. The first light-emitting elements 30A may belight-emitting elements 30 that are guided by the height differencesgenerated by the first patterns 70 to have their both ends placed on theelectrodes (21 and 22). Some of the light-emitting elements 30, e.g.,the second light-emitting elements 30B, may be located relatively high,e.g., on the first patterns 70, and may be electrically connected to thefirst and second electrodes 21 and 22.

However, the disclosure is not limited to this. As another example, thelight-emitting elements 30 may not be arranged on the first patterns 70depending on the arrangement and the shape of the first patterns 70, andthis will be described below.

In each of the light-emitting elements 30, layers may be disposed in adirection perpendicular to the top surface of the first substrate 11 orthe first planarization layer 19. The light-emitting elements 30 may bearranged so that the direction in which the light-emitting elements 30extend may be parallel to the first planarization layer 19, and thesemiconductor layers included in each of the light-emitting elements 30may be sequentially disposed in a direction parallel to the top surfaceof the first planarization layer 19. However, the disclosure is notlimited to this. As another example, the semiconductor layers includedin each of the light-emitting elements 30 may be disposed in thedirection perpendicular to the first planarization layer 19.

Both ends of each of the light-emitting elements 30 may be in electricalcontact with the contact electrodes (26 and 27). For example, aninsulating film 38 may not be formed on the ends of each of thelight-emitting elements 30 so that some of the semiconductor layersincluded in each of the light-emitting elements 30 may be exposed andmay thus be in electrical contact with the contact electrodes (26 and27), but the disclosure is not limited thereto. As another example, theinsulating film 38 may be removed from at least portions of thelight-emitting elements 30 so that sides of the semiconductor layers ofeach of the light-emitting elements 30 may be partially exposed at bothends of each of the light-emitting elements 30 and may thus be in directcontact with the contact electrodes (26 and 27).

A second insulating layer 52 may be disposed on portions of thelight-emitting elements 30. For example, the second insulating layer 52may be disposed to surround portions of the outer surfaces of thelight-emitting elements 30, but not to cover both ends of each of thelight-emitting elements 30. The contact electrodes (26 and 27) may be inelectrical contact with both ends of each of the light-emitting elements30, not covered by the second insulating layer 52. In a plan view,portions of the second insulating layer 52 on the light-emittingelements 30 may be disposed to extend in the second direction DR2 on thefirst insulating layer 51 and thus to form linear or island patterns inthe first subpixel PX1. The second insulating layer 52 may protect andfix the light-emitting elements 30 during the fabrication of the displaydevice 10.

Contact electrodes (26 and 27) and a third insulating layer 53 may bedisposed on the second insulating layer 52.

The contact electrodes (26 and 27) may extend in one direction. Firstand second contact electrodes 26 and 27 may be disposed on portions ofthe first and second electrodes 21 and 22, respectively. The firstcontact electrode 26 may be disposed on the first electrode 21, thesecond contact electrode 27 may be disposed on the second electrode 22,and the first and second contact electrodes 26 and 27 may extend in thesecond direction DR2. The first and second contact electrodes 26 and 27may be spaced apart from, and face, each other in the first directionDR1 and may form stripe patterns in the emission area EMA of the firstsubpixel PX1.

In some embodiments, the width of the first and second contactelectrodes 27 may be the same as, or smaller than, the width of thefirst and second electrodes 21 and 22. The first and second contactelectrodes 26 and 27 may be disposed to be in electrical contact withboth ends of each of the light-emitting elements 30 and to coverportions of the top surfaces of the first and second electrodes 21 and22.

The contact electrodes (26 and 27) may be in electrical contact with thelight-emitting elements 30 and the electrodes (21 and 22). Thesemiconductor layers included in each of the light-emitting elements 30may be exposed at both ends of each of the light-emitting elements 30,and the first and second contact electrodes 26 and 27 may be inelectrical contact with the light-emitting elements 30 at both ends ofeach of the light-emitting elements 30 where the semiconductor layersare exposed. The first ends of the light-emitting elements may beelectrically connected to the first electrode 21 via the first contactelectrode 26, and the second ends of the light-emitting elements 30 maybe electrically connected to the second contact electrode 22 via thesecond contact electrode 27.

One first contact electrode 26 and one second contact electrode 27 areillustrated as being disposed in the first subpixel PX1, but thedisclosure is not limited thereto. The numbers of first contactelectrodes 26 and second contact electrodes 27 may vary depending on thenumbers of first electrodes 21 and second electrodes 22 provided in thefirst subpixel PX1.

The third insulating layer 53 is disposed on the first contact electrode26. The third insulating layer 53 may electrically insulate the firstand second contact electrodes 26 and 27 from each other. The thirdinsulating layer 53 may be disposed to cover or overlap the firstcontact electrode 26 but may not be disposed on the second ends of thelight-emitting elements 30 so that the light-emitting elements 30 may bein electrical contact with the second contact electrode 27. The thirdinsulating layer 53 may be in partial contact with the first and secondcontact electrodes 26 and 27 on the top surface of the second insulatinglayer 52. A side surface of the third insulating layer 53 adjacent tothe second electrode 22 or where the second electrode 22 is disposed maybe aligned with a corresponding side surface of the second insulatinglayer 52. The third insulating layer 53 may also be disposed in thenon-emission area of the first subpixel PX1, for example, on the firstinsulating layer 51 on the first planarization layer 19, but thedisclosure is not limited thereto.

The second contact electrode 27 is disposed on the second electrode 22,the second insulating layer 52, and the third insulating layer 53. Thesecond contact electrode 27 may be in electrical contact with the secondends of the light-emitting elements 30 and an exposed portion of the topsurface of the second electrode 22. The second ends of thelight-emitting elements 30 may be electrically connected to the secondelectrode 22 via the second contact electrode 27.

The second contact electrode 27 may be in partial contact with thesecond insulating layer 52, the third insulating layer 53, the secondelectrode 22, and the light-emitting elements 30. The first and secondcontact electrodes 26 and 27 may not be in contact with the second andthird insulating layers 52 and 53, but the disclosure is not limitedthereto. In some embodiments, the third insulating layer 53 may not beprovided.

The contact electrodes (26 and 27) may include a conductive material.The contact electrodes (26 and 27) may include ITO, IZO, ITZO, or Al.For example, the contact electrodes (26 and 27) may include atransparent conductive material, and light emitted from thelight-emitting elements 30 may travel toward the electrodes (26 and 27)through the contact electrodes (26 and 27). However, the disclosure isnot limited to this.

A fourth insulating layer 54 may be disposed on the entire surface ofthe first substrate 11. The fourth insulating layer 54 may protectelements disposed on the first substrate 11 from an externalenvironment.

The first, second, third, and fourth insulating layers 51, 52, 53, and54 may include an inorganic insulating material or an organic insulatingmaterial. For example, the first, second, third, and fourth insulatinglayers 51, 52, 53, and 54 may include an inorganic insulating materialsuch as SiO_(x), SiN_(x), silicon oxynitride (SiO_(x)N_(y)), aluminumoxide (Al₂O₃), or aluminum nitride (AlN). In another example, the first,second, third, and fourth insulating layers 51, 52, 53, and 54 mayinclude an organic insulating material such as an acrylic resin, anepoxy resin, a phenolic resin, a polyamide resin, a polyimide resin, anunsaturated polyester resin, a polyphenylene resin, a polyphenylenesulfide resin, benzocyclobutene, a cardo resin, a siloxane resin, asilsesquioxane resin, polymethyl methacrylate, polycarbonate, or apolymethyl methacrylate-polycarbonate synthetic resin. However, thedisclosure is not limited to these examples.

FIG. 6 is an enlarged schematic cross-sectional view of portion QA ofFIG. 4. FIG. 7 is a schematic cross-sectional view taken along lineQ6-Q6′ of FIG. 2. Specifically, FIG. 6 illustrates an enlarged schematiccross-sectional view of portions where the first patterns 70 of FIG. 4are disposed, and FIG. 7 illustrates a schematic cross-sectional view oflight-emitting elements 30 arranged in the second direction DR2 togetherwith first patterns 70 between the first banks 40.

Referring to FIGS. 6 and 7 and further to FIGS. 3 through 5, the firstpatterns 70 may be disposed between the first banks 40 to be spacedapart from one another in the second direction DR2. The first insulatinglayer 51, which covers the first patterns 70, is disposed to conform tothe height differences generated by the first patterns 70, which aredisposed below the first insulating layer 51, between the first banks40. During the fabrication of the display device 10, ink including thelight-emitting elements 30 may be sprayed into the first subpixel PX1after the formation of the first insulating layer 51 and the second bank45. The light-emitting elements 30 may be sprayed onto the electrodes(21 and 22) while being scattered in the ink, and as the positions andthe alignment direction of the light-emitting elements 30 change due toan electric field formed on the electrodes (21 and 22), thelight-emitting elements 30 may be arranged so that both ends thereof maybe placed on the electrodes (21 and 22).

The light-emitting elements 30, scattered in the ink, may be randomlyplaced within the emission area EMA surrounded by the second bank 45 ormay be placed even in regions other than regions between the first banks40. Light-emitting elements 30 placed in the regions other than regionsbetween the first banks 40 may not be electrically connected to theelectrodes (21 and 22) and may be lost during the fabrication of thedisplay device 10. If the light-emitting element loss rate is high, theprocess yield may decrease because of the need to spray a considerableamount of ink to maintain a predetermined number of light-emittingelements 30 in each subpixel PXn.

Since the top surfaces of the first banks 40 protrude from the firstplanarization layer 19, the emission area EMA can be properly defined,and a considerable amount of light-emitting elements 30 can be guided tobe placed within the space defined by the first banks 40. Similarly,since the top surfaces of the first patterns 70 are elevated from thefirst planarization layer 19, the region between the first banks 40 canbe properly divided. The first insulating layer 51 can be located higheron the first patterns 70 than between the first patterns 70, and thelight-emitting elements 30, scattered in the ink, can be guided into theregions where the first patterns 70 are spaced apart from one another,in case that their positions change due to the electric field. Forexample, as illustrated in FIGS. 6 and 7, the first insulating layer 51may be lower between the first patterns 70 than on the first patterns 70with respect to the top surface of the first substrate 11 or the firstplanarization layer 19. Some of the light-emitting elements 30,scattered in the ink, may be guided to be disposed on portions of thefirst insulating layer 51 that are located relatively low.

The first patterns 70, like the first banks 40, can guide thelight-emitting elements 30 to be placed at particular locations in theemission area EMA, and as a result, a considerable number oflight-emitting elements 30 can be arranged between the first banks 40.Accordingly, the number of light-emitting elements 30 that may be lostduring the fabrication of the display device 10 can be reduced, and thelight-emitting elements 30 can be arranged so that both ends thereof canbe placed on the electrodes (21 and 22), between the first banks 40. Asa result, any contact defects between the contact electrodes (26 and 27)and the light-emitting elements 30 can be prevented.

The light-emitting elements 30 may include first light-emitting elements30A that are disposed not to overlap the first patterns 70 in thethickness direction, and the first light-emitting elements 30A may bearranged so that both ends thereof may be placed on the first and secondelectrodes 21 and 22. The first light-emitting elements 30A may bealigned so that both ends thereof may be placed at desired locations.However, even if the light-emitting elements 30 are disposed on thefirst patterns 70, the light-emitting elements 30 can be electricallyconnected to the electrodes (21 and 22) as long as both ends thereof canbe properly in electrical contact with the contact electrodes (26 and27).

The light-emitting elements 30 may further include second light-emittingelements 30B that are disposed to overlap the first patterns 70 in thethickness direction. Most of the light-emitting elements 30, i.e., thefirst light-emitting elements 30A, may be disposed not to overlap thefirst patterns 70, but at least some of the light-emitting elements 30may be disposed on the first patterns 70 to be in electrical contactwith the contact electrodes (26 and 27). The second light-emittingelements 30B may be disposed on the first patterns 70 to be locatedhigher than the first light-emitting elements 30A. The firstlight-emitting elements 30A may be located lower than the secondlight-emitting elements 30B with respect to the top surface of the firstsubstrate 11 or the first planarization layer 19. The height differencebetween the first light-emitting elements 30A and the secondlight-emitting elements 30B may vary depending on the thickness of thefirst patterns 70.

The first patterns 70 may be thick enough to guide the light-emittingelements 30 to be arranged therebetween by the height differencesgenerated between the first banks 40 by the first insulating layer 51. Athickness DP of the first patterns 70 may be greater than a thickness DEof the electrodes (21 and 22). The first insulating layer 51 maygenerate height differences between the first banks 40 with respect tothe top surface of the first planarization layer 19 due to the presenceof the electrodes (21 and 22). Portions of the first insulating layer 51that cover the first and second electrodes 21 and 22 may be locatedhigher than portions of the first insulating layer 51 that are disposedon the top surface of the first planarization layer 19. As the thicknessDP of the first patterns 70 is greater than the thickness DE of theelectrodes (21 and 22), portions of the first insulating layer 51 thatare disposed on the first patterns 70 may be located higher than theportions of the first insulating layer 51 that are disposed on the firstplanarization layer 19 or the electrodes (21 and 22). The first patterns70 can generate significant height differences between the first banks40, and as a result, the light-emitting elements 30 can be guided to beplaced at particular locations.

For example, a width W1 of the first patterns 70 may be smaller than adistance W3 between the first and second electrodes 21 and 22, and thefirst patterns 70 may be disposed between the first and secondelectrodes 21 and 22. The electrodes (21 and 22) may be disposed to bespaced apart from both side surfaces of each of the first patterns 70,and height differences generated between the electrodes (21 and 22) caneffectively guide the light-emitting elements 30 to be placed atparticular locations.

The width W1 of the first patterns 70 may be greater than a width W2 ofthe second insulating layer 52. The second insulating layer 52 may bedisposed to surround portions of the outer surfaces of thelight-emitting elements 30 and thus to fix the light-emitting elements30. The width W2 of the second insulating layer 52 may be smaller than alength h of the light-emitting elements 30 so that both ends of each ofthe light-emitting elements 30 may be exposed to be in electricalcontact with the contact electrodes (26 and 27). The first patterns 70may have such a predetermined width that even the second light-emittingelements 30B may be placed parallel to the top surface of the firstplanarization layer 19. If the width W1 of the first patterns 70 is toosmall, the first insulating layer 51, which is disposed on the firstpatterns 70, may not be able to provide sufficient space for thearrangement of the second light-emitting elements 30B, and the secondlight-emitting elements 30B may be slantingly arranged. The firstpatterns 70 may be formed to have a greater width than the secondinsulating layer 52 and may provide sufficient space for the arrangementof the second light-emitting elements 30B thereon.

However, the width W1 and the thickness DP of the first patterns 70 arenot particularly limited. As another example, the width W1 of the firstpatterns 70 may be identical to or greater than the distance W3 betweenthe first and second electrodes 21 and 22 and may be even greater thanthe length h of the light-emitting elements 30. The first patterns 70and the first banks 40 may be formed at the same time, or the firstpatterns 70 may be formed by a separate patterning after the formationof the first banks 40. In some embodiments, the first patterns 70 may beintegrally formed with the first planarization layer 19, which isdisposed below the first patterns 70.

The display device 10 may include first patterns 70 that are arranged inone direction between the first banks 40. During the fabrication of thedisplay device 10, most of the light-emitting elements 30 can be guidedto be aligned at particular locations, and the number of light-emittingelements 30 that may be lost from each subpixel PXn can be minimized.

FIG. 8 is a schematic partial cross-sectional view of a display deviceaccording to another embodiment of the disclosure. FIG. 8, similar toFIG. 4, illustrates a schematic cross-sectional view of first patterns70 with no light-emitting elements 30 disposed thereon.

Referring to FIG. 8, a display device 10 may not include the thirdinsulating layer 53 of FIG. 4. A second contact electrode 27 may bedisposed directly on portion of a second insulating layer 52, and firstand second contact electrodes 26 and 27 may be spaced apart from eachother over the second insulating layer 52. Even though the displaydevice 10 does not include the third insulating layer 53, the secondinsulating layer 52 includes an organic insulating material and may fixa light-emitting element 30. The first and second contact electrodes 26and 27 may be formed at the same time by a patterning process. Theembodiment of FIG. 8 is almost the same as the embodiment of FIG. 4except that the third insulating layer 53 is not provided, and thus, adetailed description thereof will be omitted.

FIG. 9 is a schematic perspective view of a light-emitting elementaccording to an embodiment of the disclosure.

Referring to FIG. 9, a light-emitting element 30 may be a light-emittingdiode (LED), particularly, an ILED having a size of several micrometersor nanometers and formed of an inorganic material. If an electric fieldis formed in a particular direction between two opposite electrodes, theILED may be aligned between the two electrodes where polarities areformed. The light-emitting element 30 may be aligned by the electricfield formed between the two electrodes.

The light-emitting element 30 may have a shape that extends in onedirection. The light-emitting element 30 may have the shape of a rod, awire, or a tube. For example, the light-emitting element 30 may have acylindrical or rod shape, but the disclosure is not limited thereto. Inanother example, the light-emitting element 30 may have the shape of apolygonal column such as a regular cube, a rectangular parallelepiped,or a hexagonal column or may have a shape that extends in one directionand has a partially inclined outer surface. Semiconductors included inthe light-emitting element 30 may be sequentially disposed or stacked inthe direction in which the light-emitting element 30 extends.

The light-emitting element 30 may include semiconductor layers dopedwith impurities of an arbitrary conductivity type (e.g., a p-type or ann-type). The semiconductor layers may receive electrical signals from anexternal power source to emit light of a particular wavelength range.

Referring to FIG. 9, the light-emitting element 30 may include a firstsemiconductor layer 31, a second semiconductor layer 32, alight-emitting layer 36, an electrode layer 37, and an insulating film38.

The first semiconductor layer 31 may include an n-type semiconductor.For example, in a case where the light-emitting element 30 emits lightof a blue wavelength range, the first semiconductor layer 31 may includea semiconductor material Al_(x)Ga_(y)In_(1−x−y)N (where 0≤x≤1, 0≤y≤1,and 0≤x+y≤1). For example, the semiconductor materialAl_(x)Ga_(y)In_(1−x−y)N may be at least one of AlGaInN, GaN, AlGaN,InGaN, AlN, and InN that are doped with an n-type dopant. The firstsemiconductor layer 31 may be doped with an n-type dopant, and then-type dopant may be, for example, Si, Ge, or Sn. For example, the firstsemiconductor layer 31 may be n-GaN doped with n-type Si. The firstsemiconductor layer 31 may have a length of about 1.5 μm to about 5 μm,but the disclosure is not limited thereto.

The second semiconductor layer 32 is disposed on the light-emittinglayer 36. The second semiconductor layer 32 may include a p-typesemiconductor. For example, in a case where the light-emitting element30 emits light of a blue or green wavelength range, the secondsemiconductor layer 32 may include a semiconductor materialAl_(x)Ga_(y)In_(1−x−y)N (where 0≤x≤1, 0≤y≤1, and 0≤x+y≤1). For example,the semiconductor material Al_(x)Ga_(y)In_(1−x−y)N may be at least oneof AlGaInN, GaN, AlGaN, InGaN, AlN, and InN that are doped with a p-typedopant. The second semiconductor layer 32 may be doped with a p-typedopant, and the p-type dopant may be, for example, Mg, Zn, Ca, Se, orBa. For example, the second semiconductor layer 32 may be p-GaN dopedwith p-type Mg. The second semiconductor layer 32 may have a length ofabout 0.05 μm to about 0.10 μm, but the disclosure is not limitedthereto.

The first and second semiconductor layers 31 and 32 are illustrated asbeing formed as single-layer films, but the disclosure is not limitedthereto. As another example, each of the first and second semiconductorlayers 31 and 32 may include more than one layer such as, for example, aclad layer or a tensile strain barrier reducing (TSBR) layer, dependingon the material of the light-emitting layer 36.

The light-emitting layer 36 is disposed between the first and secondsemiconductor layers 31 and 32. The light-emitting layer 36 may includea single- or multi-quantum well structure material. In a case where thelight-emitting layer 36 includes a material having a multi-quantum wellstructure, the light-emitting layer 36 may have a structure in whichmultiple quantum layers and multiple well layers are alternatelystacked. The light-emitting layer 36 may emit light by combiningelectron-hole pairs in accordance with electrical signals appliedthereto via the first and second semiconductor layers 31 and 32. Forexample, in a case where the light-emitting layer 36 emits light of ablue wavelength range, the quantum layers may include a material such asAlGaN or AlGaInN. In particular, in a case where the light-emittinglayer 36 has a multi-quantum well structure in which multiple quantumlayers and multiple well layers are alternately stacked, the quantumlayers may include a material such as AlGaN or AlGaInN, and the welllayers may include a material such as GaN or AlInN. In a case where thelight-emitting layer 36 includes AlGaInN as its quantum layer(s) andAlInN as its well layer(s), the light-emitting layer 36 can emit bluelight having a central wavelength range of about 450 nm to about 495 nm.

However, the disclosure is not limited to this. As another example, thelight-emitting layer 36 may have a structure in which a semiconductormaterial having a large band gap energy and a semiconductor materialhaving a small band gap energy are alternately stacked or may includegroup III or group V semiconductor materials depending on the wavelengthof light to be emitted. The type of light emitted by the light-emittinglayer 36 is not particularly limited. The light-emitting layer 36 mayemit light of a red or green wavelength range as necessary, instead ofblue light. The light-emitting layer 36 may have a length of about 0.05μm to about 0.10 μm, but the disclosure is not limited thereto.

Light may be emitted not only from the circumferential surface, in alength direction, of the light-emitting element 30, but also from bothsides of the light-emitting element 30. The directionality of the lightemitted from the light-emitting layer 36 is not particularly limited.

The electrode layer 37 may be an ohmic contact electrode, but thedisclosure is not limited thereto. As another example, the electrodelayer 37 may be a Schottky contact electrode. The light-emitting element30 may include at least one electrode layer 37. FIG. 9 illustrates thatthe light-emitting element 30 includes one electrode layer 37, but thedisclosure is not limited thereto. As another example, thelight-emitting element 30 may include more than one electrode layer 37,or the electrode layer 37 may not be provided. However, the followingdescription of the light-emitting element 30 may be directly applicableto a light-emitting element 30 having more than one electrode layer 37or having a different structure from the light-emitting element 30 ofFIG. 9.

The electrode layer 37 may reduce the resistance between thelight-emitting element 30 and electrodes (or contact electrodes) in casethat the light-emitting element 30 is electrically connected to theelectrodes (or the contact electrodes). The electrode layer 37 mayinclude a conductive metal. For example, the electrode layer 37 mayinclude at least one of Al, Ti, In, Au, Ag, ITO, IZO, and ITZO. Also,the electrode layer 37 may include a semiconductor material doped withan n- or p-type dopant. The electrode layer 37 may include the samematerial or different materials, but the disclosure is not limitedthereto.

The insulating film 38 is disposed to surround the first and secondsemiconductor layers 31 and 32 and the electrode layer 37. For example,the insulating film 38 may be disposed to surround at least thelight-emitting layer 36 and may extend in the direction in which thelight-emitting element 30 extends. The insulating film 38 may protectthe first semiconductor layer 31, the light-emitting layer 36, thesecond semiconductor layer 32, and the electrode layer 37. For example,the insulating film 38 may be formed to surround the sides of the firstsemiconductor layer 31, the light-emitting layer 36, the secondsemiconductor layer 32, and the electrode layer 37, but to expose bothends, in the length direction, of the light-emitting element 30.

The insulating film 38 is illustrated as being formed to extend in thelength direction of the light-emitting element 30 and to cover the sidesof the first semiconductor layer 31, the light-emitting layer 36, thesecond semiconductor layer 32, and the electrode layer 37, but thedisclosure is not limited thereto. The insulating film 38 may cover thesides of only the light-emitting layer 36 and some of the first andsecond semiconductor layers 31 and 32 or may cover only portion of theside of the electrode layer 37 so that the side of the electrode layer37 may be partially exposed. The insulating film 38 may be formed to berounded in a cross-sectional view, in a region adjacent to at least oneend of the light-emitting element 30.

The insulating film 38 may have a thickness of about 10 nm to about 1.0

, but the disclosure is not limited thereto. The insulating film 38 mayhave a thickness of about 40 nm.

The insulating film 38 may include a material with insulating propertiessuch as, for example, SiO_(x), SiN_(x), SiO_(x)N_(y), AlN, or Al₂O₃.Accordingly, the insulating film 38 can prevent any short circuit thatmay occur in case that the light-emitting layer 36 is placed in directcontact with electrodes that transmit electrical signals directly to thelight-emitting element 30. Since the insulating film 38 includes thelight-emitting layer 36 to protect the outer surface of thelight-emitting element 30, any degradation in the emission efficiency ofthe light-emitting element 30 can be prevented.

In some embodiments, the outer surface of the insulating film 38 may besubjected to surface treatment. The light-emitting element 30 may besprayed on electrodes while being scattered in predetermined ink. Here,the surface of the insulating film 38 may be hydrophobically orhydrophilically treated to keep the light-emitting element 30 scatteredin ink without agglomerating with other neighboring light-emittingelements 30.

A length h of the light-emitting element 30 may be in the range of about1 urn to about 10

, about 2

to about 6

, or about 3

to about 5

. The light-emitting element 30 may have a diameter of about 30 nm toabout 700 nm and may have an aspect ratio of 1.2 to 100, but thedisclosure is not limited thereto. Different light-emitting elements 30included in the display device 10 may have different diameters dependingon the composition of their respective light-emitting layers 36. Forexample, the light-emitting element 30 may have a diameter of about 500nm.

A method of fabricating the display device 10 will hereinafter bedescribed.

FIGS. 10 through 12 are schematic cross-sectional views illustratingprocesses of a method of fabricating a display device according to anembodiment of the disclosure. FIG. 13 is a schematic plan view of asubpixel obtained by the process(es) illustrated in FIG. 12.

Referring first to FIG. 10, a target substrate SUB where a firstinsulating layer 51 and electrodes (21 and 22) are disposed is prepared.Although not specifically illustrated, the target substrate SUB mayinclude a first substrate 11 and may further include circuit elementsthat include conductive layers and insulating layers. For convenience,the first substrate 11 and the circuit elements will hereinafter becollectively referred to as the target substrate SUB.

Thereafter, first banks 40 are formed on the target substrate SUB to bespaced apart from each other. As already mentioned above, the firstbanks 40 may protrude from the top surface of the target substrate SUB.

Thereafter, referring to FIG. 11, first patterns 70 are formed betweenthe first banks 40, on the target substrate SUB. The first patterns 70may be spaced apart from the first banks 40 and may have a smallerthickness than the first banks 40. The first patterns 70 are illustratedas being formed after the formation of the first banks 40, but thedisclosure is not limited thereto. As another example, the firstpatterns 70 and the first banks 40 may include the same materials andmay be formed at the same time. For example, the first banks 40 and thefirst patterns 70, which have a different thickness from the first banks40, may be formed at the same time using a halftone mask during theformation of the first banks 40.

Thereafter, referring to FIGS. 12 and 13, first and second electrodelayers 21′ and 22′ are formed on the first banks 40. The first andsecond electrode layers 21′ and 22′ extend in a second direction DR2 andare spaced apart from each other with the first patterns 70therebetween. The first and second electrode layers 21′ and 22′ mayextend in the second direction DR2 to be disposed in other subpixels PXnduring the fabrication of a display device 10. The first and secondelectrode layers 21′ and 22′ may be cut in a cut area CBA of eachsubpixel PXn after the arrangement of light-emitting elements 30 and maythen be formed into first and second electrodes 21 and 22, respectively.

The first patterns 70 may be arranged between the first banks 40 orbetween the first and second electrode layers 21′ and 22′ to be spacedapart from one another in the second direction DR2. The region betweenthe first banks 40 may be divided into regions where the first patterns70 are disposed and regions where the first patterns 70 are notdisposed, and the regions where the first patterns 70 are disposed mayhave a different height from the regions where the first patterns 70 arenot disposed. Thereafter, a first insulating layer 51, which covers thefirst patterns 70 and the first and second electrode layers 21′ and 22′,and a second bank 45, which is disposed on the first insulating layer51, are formed, and the light-emitting elements 30 are disposed betweenthe first banks 40.

FIGS. 14 and 15 are schematic cross-sectional views illustratingprocesses of the method of fabricating a display device according to anembodiment of the disclosure.

Referring to FIGS. 14 and 15, a first insulating material layer 51′,which covers the first patterns 70 and electrode layers (21′ and 22′),is formed, and the second bank 45, which is disposed on the firstinsulating material layer 51′ and surrounds an emission area EMA and thecut area CBA of each subpixel PXn, is formed. The first insulatingmaterial layer 51′ may be disposed on the entire surface of the targetsubstrate SUB and may cover the first patterns 70 and the electrodelayers (21′ and 22′). The first insulating material layer 51′ may bepartially removed in a subsequent process so that the top surfaces ofthe electrode layers (21′ and 22′) may be exposed, and as a result, thefirst insulating layer 51 may be formed. As already mentioned above, thesecond bank 45 may be disposed to surround and separate each subpixelPXn and may also separate the emission area EMA and the cut area CBA ofeach subpixel PXn.

FIG. 16 is a schematic plan view of a subpixel obtained by the processesillustrated in FIGS. 14 and 15. FIGS. 17 through 19 are schematiccross-sectional views illustrating the arrangement of light-emittingelements and first patterns in the subpixel of FIG. 16. Specifically,FIG. 17 illustrates light-emitting elements 30 disposed in regions wherefirst patterns 70 are not disposed, and FIG. 18 illustrateslight-emitting elements 30 disposed in regions where the first patterns70 are disposed. FIG. 19 illustrates light-emitting elements 30 disposedbetween the first patterns 70, which are spaced apart from each other inthe second direction DR2.

Referring to FIGS. 16 through 19, light-emitting elements 30 aredisposed between the first banks 40. The light-emitting elements 30 maybe disposed so that both ends thereof may be placed on the first andsecond electrode layers 21′ and 22′. The light-emitting elements 30 maybe sprayed onto the target substrate SUB while being scattered in ink.For example, the light-emitting elements 30 may be prepared to bescattered in ink and may then be sprayed onto the target substrate SUBby a printing process using an inkjet printing device. The ink sprayedby the inkjet printing device may be settled within each regionsurrounded by the second bank 45. The second bank 45 may prevent the inkfrom spilling over between different pixels PXn.

Once the ink including the light-emitting elements 30 is sprayed, thelight-emitting elements 30 may be arranged on the first insulatingmaterial layer 51′ by applying electrical signals to the electrodelayers (21′ and 22′). As the electrical signals are applied to theelectrode layers (21′ and 22′), an electric field may be generatedbetween the electrode layers (21′ and 22′). The light-emitting elements30 scattered in the ink may receive a dielectrophoretic force from theelectric field, and as a result, the alignment direction and thepositions of the light-emitting elements 30 may change so that thelight-emitting elements 30 may be settled on the first insulatingmaterial layer 51′. Here, some of the light-emitting elements 30, i.e.,light-emitting elements 30A, may be disposed between the first patterns70, as illustrated in FIG. 17, and some of the light-emitting elements30, e.g., light-emitting elements 30B, may be disposed on the firstpatterns 70, as illustrated in FIG. 18. Also, some of the first patterns70 may have no light-emitting elements 30 disposed thereon. The firstpatterns 70 may guide the light-emitting elements 30 to be placed sothat each of both ends of each of the light-emitting elements 30 may bearranged on corresponding one of electrodes (21 and 22) or on theelectrode layers (21′ and 22′), and most of the light-emitting elements30 may be arranged at locations relatively lower than the first patterns70. However, as illustrated in FIG. 5, at least some of thelight-emitting element 30 may be disposed on the first patterns 70, andeven these light-emitting elements 30 may be electrically connected tothe electrodes (21 and 22) via contact electrodes (26 and 27).

FIGS. 20 and 21 are schematic cross-sectional views illustratingprocesses of the method of fabricating a display device according to anembodiment of the disclosure. Specifically, FIGS. 20 and 21 illustrateschematic cross-sectional views of first patterns 70 having nolight-emitting elements 30 disposed thereon.

Referring to FIG. 21, the first insulating layer 51 may be formed byremoving portions of the first insulating material layer 51′ to exposethe top surfaces of the first and second electrode layers 21′ and 22′.The first insulating layer 51 may include openings OP, which exposeportions of the electrode layers (21′ and 22′). The top surfaces of theelectrode layers (21′ and 22′), exposed by the openings OP, may be inelectrical contact with the contact electrodes (26 and 27).

Thereafter, the first and second electrodes 21 and 22 are formed bycutting the first and second electrode layers 21′ and 22′ in the cutarea CBA of each subpixel PXn, and a second insulating layer 52, a thirdinsulating layer 53, and the contact electrodes (26 and 27) are formedon the light-emitting elements 30. Electrical signals for the alignmentof the light-emitting elements 30 may be applied to the electrode layers(21′ and 22′) electrically connected to each subpixel PXn. For thedriving of the display device 10, however, the electrode layers (21′ and22′) may be cut and separated in the cut area CBA of each subpixel PXn,thereby forming the electrodes (21 and 22), and as a result, theelectrodes (21 and 22) can be driven separately via a first transistorTR1 of each subpixel PXn.

Thereafter, although not specifically illustrated, a fourth insulatinglayer 54, which covers the elements disposed on the target substrateSUB, may be formed, thereby fabricating the display device 10.

Display devices according to other embodiments of the disclosure willhereinafter be described.

A display device 10 includes first patterns 70, which are disposedbetween first banks 40, in each subpixel PXn. FIG. 6 illustrates thatthe width W1 of the first patterns 70 is smaller than the distance W3between the electrodes (21 and 22), but the disclosure is not limitedthereto. For example, the width W1 and the thickness DP of the firstpatterns 70 may vary as long as the light-emitting elements 30 can beproperly guided to be aligned at particular locations.

FIGS. 22 through 24 are schematic partial cross-sectional views ofdisplay devices according to other embodiments of the disclosure.Specifically, FIGS. 22 and 23 illustrate schematic cross-sectional viewsof first patterns 70_1 or 70_2 having no light-emitting elements 30disposed thereon, and FIG. 24 illustrate a schematic cross-sectionalview of first patterns 703 having second light-emitting elements 30Bdisposed thereon.

Referring to FIG. 22, a width W1 of first patterns 70_1 may be the sameas a distance W3 between electrodes (21_1 and 22_1), and the firstpatterns 701 may be in electrical contact with the electrodes (21_1 and22_1). The first patterns 701 may be formed to have a relatively largewidth W1 and to be in electrical contact with the electrodes (21_1 and22_1), and a first insulating layer 51, which is disposed on the firstpatterns 701, may provide space in which second light-emitting elements30B can be horizontally arranged.

Referring to FIG. 23, a width W1 of first patterns 70_2 may be greaterthan a distance W3 between electrodes (21_2 and 22_2), and first sidesof the electrodes (21_2 and 22_2) may be disposed on the first patterns70_2. The embodiment of FIG. 23 differs from the other embodiments atleast in that the first sides of the electrodes (21_2 and 22_2) aredisposed on the first patterns 70_2 because of the first patterns 70_2having a relatively large width W1. Although not specificallyillustrated, second light-emitting elements 30B disposed on the firstpatterns 70_2 may be arranged so that both ends thereof may be placed onthe electrodes (21_2 and 22_2), and as a result, the secondlight-emitting elements 30B can be properly in electrical contact withcontact electrodes (26 and 27). In the embodiment of FIG. 23, unlike inthe embodiment of FIG. 5, the number of light-emitting elements 30electrically connected to the electrodes (21_2 and 22_2), between firstbanks 40, can be further increased.

In case that first patterns 70 have a relatively small width, secondlight-emitting elements 30B may not be able to be properly in electricalcontact with contact electrodes (26 and 27). Light-emitting elements 30may be inclined, rather than being horizontally arranged, depending onthe width of the first patterns 70, and electrical signals may not beable to be properly transmitted to the light-emitting elements 30 due tocontact defects. By controlling the thickness of the first patterns 70,the light-emitting elements 30 can be guided to be placed between thefirst patterns 70, rather than on the first patterns 70, in case thatthe light emitting elements 30 are aligned by an electric field.

Referring to FIG. 24, a thickness DP_3 of first patterns 70_3 may begreater than a thickness DE of electrodes (21 and 22), but smaller thana diameter DN of light-emitting elements 30. In case that the thicknessDP_3 of the first patterns 70_3 is smaller than the diameter DN of thelight-emitting elements 30, the light-emitting elements 30 can be easilymoved away from above the first patterns 70_3 by an electric fieldduring the fabrication of a display device 10. If an electric field isgenerated for aligning the light-emitting elements 30 and is continuedfor more than a predetermined amount of time, light-emitting elements 30disposed on the first patterns 70_3 may be moved to locations where thefirst patterns 70_3 are not disposed. Even light-emitting elements 30disposed in regions other than that between first banks 40 can be movedover the first patterns 70_3. Second light-emitting elements 30B areillustrated as being disposed on the first patterns 703, but in anembodiment, a considerable number of light-emitting elements 30, similarto first light-emitting elements 30A, can be disposed not to overlap thefirst patterns 703. Since the first patterns 70_3 have a smallerthickness DP_3 than the diameter DN of the light-emitting elements 30,most of the light-emitting elements 30 can be arranged similar to thefirst light-emitting elements 30A. For example, the thickness DP_3 ofthe first patterns 703 may be smaller than half the diameter DN of thelight-emitting elements 30.

The shape of first patterns 70 may vary as long as the first patterns 70can generate height differences between first banks 40 and can properlyguide light-emitting elements 30 to be placed at particular locations.For example, the shape of the first patterns 70 may vary as long as atleast some light-emitting elements 30 electrically connected to firstand second electrodes 21 and 22 can be located higher or lower thanother light-emitting elements 30.

FIGS. 25 and 26 are schematic partial cross-sectional views of displaydevices according to other embodiments of the disclosure.

Specifically, FIG. 25 illustrates a schematic cross-section view offirst patterns 70_4 with no light-emitting elements 30 disposed thereon.Referring to FIG. 25, the first patterns 704 may be integrally formedwith (or integral with) a first planarization layer 19, which isdisposed below the first patterns 70_4. During the formation of thefirst planarization layer 19, portions of the top surface of the firstplanarization layer 19 may be formed to protrude and thus to form thefirst patterns 70_4. The first patterns 704 may be formed in variousprocesses during the fabrication of a display device 10. As alreadymentioned above, the first patterns 70_4 may be formed during or afterthe formation of the first banks 40, and the first patterns 70_4 may beformed by making portions of the top surface of the first planarizationlayer 19 protrude. The embodiment of FIG. 25 differs from the embodimentof FIG. 5 at least in that the first patterns 70_4 are integrally formedwith the first planarization layer 19. The first planarization layer 19may include the first patterns 70_4, which are formed as protrusionsfrom the top surface of the first planarization layer 19, and portionswhere the first patterns 70_4 are not formed. Among light-emittingelements 30, first light-emitting elements 30A may be disposed on theportions of the first planarization layer 19 where the first patterns70_4 are not formed, and second light-emitting elements 30B may bedisposed on the first patterns 70_4. Most of the light-emitting elements30 can be guided to be placed between the first patterns 70_4, ratherthan on the first patterns 70_4, during the fabrication of the displaydevice 10.

Referring to FIG. 26, a first planarization layer 19_5 may includerecesses where portions the top surface of the first planarization layer19_5 are depressed between first banks 40, and at least some oflight-emitting elements 30 may be disposed in the recesses. During theformation of the first planarization layer 195, the recesses may beformed between the first banks 40. During the fabrication of a displaydevice 10, a process of generating height differences may be performedto allow the light-emitting elements 30 to be placed at differentlocations. For example, after the formation of the first planarizationlayer 195, the recesses may be formed between the first banks 40 duringthe formation of first and second contact holes CT1 and CT2. As therecesses are formed between the first banks 40, height differences aregenerated in a second direction DR2, and the light-emitting elements 30disposed between the first banks 40 may be arranged to have differentheights from the top surface of a first substrate 11. The embodiment ofFIG. 26 differs from the other embodiments at least in that portions ofthe top surface of the first planarization layer 19_5 are depressed.

For example, a width W4 of the recesses may be greater than a distanceW3 between electrodes (21_5 and 22_5), and at least a portion of theelectrodes (21_5 and 22_5) may be disposed in the recesses. Thelight-emitting elements 30 can be guided to be moved into the recessesby an electric field, and some or most of the light-emitting elements 30can be disposed in the recesses. First light-emitting elements 30A areillustrated as being disposed in the recesses, but the disclosure is notlimited thereto. The light-emitting elements 30 may further includesecond light-emitting elements 30B, which are disposed on portions ofthe first planarization layer 19_5 where the recesses are not formed andare located higher than the first light-emitting elements 30A.

The shape of the first patterns 70, 70_1, 70_2, 70_3, and 70_4 is notparticularly limited. The first patterns 70, 70_1, 70_2, 70_3, and 70_4are illustrated as having a rectangular shape in a plan view or across-sectional view, but the disclosure is not limited thereto.

FIG. 27 is a schematic partial cross-sectional view of a display deviceaccording to another embodiment of the disclosure. FIG. 28 is aschematic plan view of a subpixel of the display device of FIG. 27.

Referring to FIGS. 27 and 28, the top surfaces of first patterns 70_6may be curved. In some embodiments, the first patterns 70_6 may have ahemispherical shape and/or may be circular in a plan view andsemicircular in a cross-sectional view. Portions of a first insulatinglayer 51_6 on the first patterns 70_6 may not have a flat top surface,and the positions of light-emitting elements 30 disposed on the portionsof the first insulating layer 51_6 may be changed by an electric fieldso that the light-emitting elements 30 may not overlap the firstpatterns 70_6. As a result, the light-emitting elements 30 may not bedisposed on the first patterns 70_6, and portions of a second insulatinglayer 52_6 that overlap the first patterns 70_6 may be in direct contactwith the first insulating layer 51_6. The embodiment of FIGS. 27 and 28differs from the other embodiments at least in that the first patterns70_6 may have a curved top surface and only first light-emittingelements 30A (and no second light-emitting elements 30B) are provided.

FIG. 29 is a schematic plan view of a subpixel of a display deviceaccording to another embodiment of the disclosure. FIG. 30 is aschematic cross-sectional view taken along line QB-QB′ of FIG. 29. FIG.31 is a schematic plan view of a subpixel of a display device accordingto another embodiment of the disclosure. FIG. 32 is a schematiccross-sectional view taken along lines QC-QC′, QD-QD′, and QE-QE′ ofFIG. 31. FIGS. 30 and 32 illustrate schematic cross-sectional views,taken in a second direction DR2, of first patterns 70_7 andlight-emitting elements 30.

Referring to FIGS. 29 through 32, first patterns 70_7 or 70_8 may bedisposed to overlap a first electrode 21 or a second electrode 22. Thefirst patterns 70_7 or 70_8 may be disposed directly on a firstplanarization layer 19 where the first and second electrodes 21 and 22are disposed and may generate height differences in the first and secondelectrodes 21 and 22. The first patterns 70_7 or 70_8 may have such asmall width that light-emitting elements 30 can be easily moved awayfrom the first patterns 70_7 or 70_8 even if they are disposed on thefirst patterns 70_7 or 70_8, and may be disposed to overlap electrodes(21 and 22). In the embodiments of FIGS. 29 through 32, unlike in anembodiment where the first patterns 70_7 or 70_8 are disposed betweenthe electrodes (21 and 22), some or most of the light-emitting elements30 (e.g., first light-emitting elements 30A of FIGS. 30 and 32) can bedisposed not to overlap the first patterns 70_7 or 70_8 because heightdifferences are generated in portions of the electrodes (21 and 22)where the ends of the light-emitting elements 30 are disposed.

In some embodiments, first patterns 70_7 or 70_8 that overlap the firstelectrode 21 and first patterns 70_7 or 70_8 that overlap the secondelectrode 22 may be arranged either parallel to each other or in astaggered manner between first banks 40. For example, as illustrated inFIGS. 29 and 30, the first patterns 70_7 or 70_8 that overlap the firstelectrode 21 and the first patterns 70_7 or 70_8 that overlap the secondelectrode 22 may be arranged parallel to each other between the firstbanks 40. In another example, as illustrated in FIGS. 31 and 32, thefirst patterns 70_7 or 70_8 that overlap the first electrode 21 and thefirst patterns 70_7 or 70_8 that overlap the second electrode 22 may bearranged in a staggered manner between the first banks 40.

During the fabrication of a display device 10, even if first ends of thelight-emitting elements 30 are disposed on the first patterns 70_7 or70_8, second ends of the light-emitting elements 30 may not be disposedon the first patterns 70_7 or 70_8, or vice versa. In this case, in thepresence of an electric field, the light-emitting elements 30 can bemoved to regions where the first patterns 70_7 or 70_8 are not formed.Since the first patterns 70_7 or 70_8 have a relatively small width andare disposed to overlap the electrodes (21 and 22), the light-emittingelements 30 can be properly guided toward locations where the firstpatterns 70_7 or 70_8 are not disposed, even if ends of thelight-emitting elements 30 are disposed on the first patterns 70_7 or70_8.

The first and second electrodes 21 and 22 may not necessarily extend inone direction. In some embodiments, the electrodes (21 and 22) mayinclude portions that extend in one direction to have different widthsand portions that extend in another direction.

FIG. 33 is a schematic plan view of a subpixel of a display deviceaccording to another embodiment of the disclosure.

Referring to FIG. 33, each of electrodes (21_9 and 22_9) may include anextended portion RE-E, which generally extends in a second direction andhas a greater width than the rest of the corresponding electrode, bentportions (RE-B1 and RE-B2), which extend in a diagonal direction withrespect to a first direction DR1 or the second direction DR2, andconnecting portions (RE-C1 and RE-C2), which connect the bent portions(RE-B1 and RE-B2) and the extended portion RE-E. The electrodes (21_9and 22_9) may generally extend in the second direction DR2 but may havea relatively large width in portion or may be bent in a diagonaldirection with respect to the second direction DR2. First and secondelectrodes 21_9 and 22_9 may be arranged symmetrically with respect to afirst pattern 70_9 disposed therebetween. The shape of the firstelectrode 21_9 will hereinafter be described.

The first electrode 21_9 may include an extended portion RE-E, which hasa greater width than the rest of the first electrode 21_9. Extendedportions RE-E of the first and second electrodes 21_9 and 22_9 may bedisposed on first banks 40, in an emission area EMA of a first subpixelPX1, to extend in the second direction DR2. The first pattern 70_9 maybe disposed between the extended portions RE-E, and light-emittingelements 30 may be disposed on the extended portions RE-E. First andsecond contact electrodes 26_9 and 27_9 may be disposed on the extendedportions RE-E but may have a smaller width than the extended portionsRE-E.

Connecting portions (RE-C1 and RE-C2) may extend or be connected to bothsides, in the second direction DR2, of each of the extended portionRE-E. First connecting portions RE-C1 may be disposed on first sides, inthe second direction DR2, of the extended portions RE-E, and secondconnecting portions RE-C2 may be disposed on second sides, in the seconddirection DR2, of the extended portions RE-E. The connecting portions(RE-C1 and RE-C2) may extend or be connected to the extended portionsRE-E of the corresponding electrode and may be disposed in and acrossthe emission area EMA and a second bank 45.

The first connecting portions RE-C1 and the second connecting portionsRE-C2 may have a smaller width than the extended portions RE-E. Firstsides of the connecting portions (RE-C1 and RE-C2) that extend in thesecond direction DR2 may extend or be connected to, and fall on the sameline as, a first side of the respective extended portion RE-E thatextends in the second direction DR2. For example, an outer side of theextended portion RE-E of each of the electrodes (21_9 and 22_9) mayextend to be electrically connected to outer sides of the connectingportions (RE-C1 and RE-C2) of the corresponding electrode. Accordingly,a distance DE1 between the extended portions RE-E of the first andsecond electrodes 21_9 and 22_9 may be smaller than a distance DE2between the connecting portions (RE-C1 and RE-C2) of the first andsecond electrodes 21_9 and 22_9.

Bent portions (RE-B1 and RE-B2) extend or are connected to theconnecting portions (RE-C1 and RE-C2). The bent portions (RE-B1 andRE-B2) may include first bent portions RE-B1, which extend or areconnected to first connecting portions RE-C1 and are disposed on thesecond bank 45 and in a cut area CBA, and second bent portions RE-B2,which extend or are connected to second connecting portions RE-C2 andare disposed on the second bank 45 and in a cut area CBA of anothersubpixel PXn. The bent portions (RE-B1 and RE-B2) may be electricallyconnected to the connecting portions (RE-C1 and RE-C2) and may be bentin a diagonal direction with respect to the second direction DR2, forexample, in a direction toward the center of the first subpixel PX1. Aminimum distance DE3 between the bent portions (RE-B1 and RE-B2) may besmaller than the distance DE2 between the connecting portions (RE-C1 andRE-C2) but may be greater than the distance DE1 between the extendedportions RE-E.

Contact portions RE-P may be formed in regions where the firstconnecting portions RE-C1 and the first bent portions RE-B1 areelectrically connected. The contact portions RE-P may overlap the secondbank 45 so that first and second contact holes CT1 and CT2 of the firstand second electrodes 21_9 and 22_9 may be formed.

Fragment portions RE-D, which are obtained when the first and secondelectrodes 21_9 and 22_9 are separated into pieces in the cut area CBA,may be formed at first ends of the first bent portions RE-B1. Thefragment portions RE-D may be portions of first and second electrodes21_9 and 22_9 of a neighboring subpixel PXn in the second direction DR2that remain in the cut area CBA.

The embodiment of FIG. 33 differs from the embodiment of FIG. 4 at leastin that each of the first and second electrodes 21_9 and 22_9 includesan extended portions RE-E, connecting portions (RE-C1 and RE-C2), andbent portions (RE-B1 and RE-B2) and are arranged symmetrically withrespect to the center of the first subpixel PX1. However, the disclosureis not limited to this. As another example, the first and secondelectrodes 21_9 and 22_9 may have different shapes.

FIG. 34 is a schematic plan view of a subpixel of a display deviceaccording to another embodiment of the disclosure. FIG. 35 is aschematic cross-sectional view taken along line QX-QX′ of FIG. 34.

Referring to FIGS. 34 and 35, a display device 10 may include, in eachsubpixel PXn thereof, for example, in a first subpixel PX1, firstelectrodes 21_10, second electrodes 22_10, and first patterns 70_10. Thefirst electrodes 21_10 may have the same shape as their counterpart ofFIG. 28, and first electrodes 21_10, for example, two first electrodes21_10, may be arranged symmetrically with respect to the center of thefirst subpixel PX1. The second electrodes 22_10 may have the same shapeas their counterpart of FIG. 2, and second electrodes 22_10, forexample, two second electrodes 22_10, may be arranged between the firstelectrodes 21_10. The distance between the first electrodes 21_10 andthe second electrodes 22_10 may differ from one location to anotherlocation on the first electrodes 21_10. For example, a distance DE1between extended portions RE-E of the first electrodes 21_10 and thesecond electrodes 22_10 may be smaller than a distance DE2 betweenconnecting portions (RE-C1 and RE-C2) of the first electrodes 21_10 andthe second electrodes 22_10 and a distance DE3 between bent portions(RE-B1 and RE-B2) of the first electrodes 21_10 and the secondelectrodes 22_10. The distance DE2 between the connecting portions(RE-C1 and RE-C2) of the first electrodes 21_10 and the secondelectrodes 22_10 may be greater than the distance DE3 between the bentportions (RE-B1 and RE-B2) of the first electrodes 21_10 and the secondelectrodes 22_10. However, the disclosure is not limited to this. Theshapes of electrodes (21_10 and 22_10) is the same as the shapes oftheir respective counterparts of any one of FIGS. 2 through 33, andthus, detailed descriptions thereof will be omitted.

The arrangement and the shapes of first banks 41_10, a first insulatinglayer 51_10, and contact electrodes (26_10, 27_10, and 28_10) may varydepending on the arrangement of the first electrodes 21_10 and thesecond electrodes 22_10.

The first insulating layer 51_10 may be disposed between, and be incontact with, the extended portions RE-E of the first electrodes 21_10and the second electrodes 22_10. First ends of light-emitting elements30 may be disposed on the extended portions RE-E of the first electrodes21_10, and second ends of the light-emitting elements 30 may be disposedon the second electrodes 22_10.

The first banks 40 may include first sub-banks 41_10 and a secondsub-bank 42_10. The first sub-banks 41_10 and the second sub-bank 42_10may extend in a second direction DR2, and the first sub-banks 41_10 mayhave a different width in a first direction DR1 than the second sub-bank42_10. As the first sub-banks 41_10 have a larger width in the firstdirection DR1 than the second sub-bank 42_10, the first sub-banks 41_10may be disposed across the boundaries between the first subpixel PX1 andneighboring subpixels PXn, in the first direction DR1, of the firstsubpixel PX1. For example, the first sub-banks 41_10 may be disposed notonly in an emission area EMA of the first subpixel PX1, but also betweenthe emission area EMA of the first subpixel PX1 and emission areas EMAof the neighboring subpixels PXn. Accordingly, portions of a second bank45_10 that extend in the second direction DR2 may be disposed on thefirst sub-banks 41_10. Two first sub-banks 41_10 may be disposed inportion in each subpixel PXn, and one second sub-bank 42_10 may bedisposed between the two first sub-banks 41_10.

The second sub-bank 42_10 may extend in the second direction DR2 in themiddle of the emission area EMA of the first subpixel PX1. The secondsub-bank 42_10 may have a smaller width than the first sub-banks 41_10and may be spaced apart from the first sub-banks 41_10.

The extended portions RE-E of the first electrodes 21_10 and the secondbank 45_10 may be disposed on the first sub-banks 41_10. Extendedportions RE-E of first electrodes 21_10 of the neighboring subpixels PXnmay be disposed on the first sub-banks 41_10. For example, extendedportions RE-E of two first electrodes 21_10 may be disposed on one firstsub-bank 41_10, and two second electrodes 22_10 may be disposed on onesecond sub-bank 42_10. The second electrodes 22_10 may be disposed alongboth sides of the second sub-bank 42_10 that extend in the seconddirection DR2 and may be spaced apart from each other with the secondsub-bank 42_10 therebetween.

One of the first electrodes 21_10 may include a contact portion RE-P, inwhich a first contact hole CT1 is formed, and the other first electrode21_10 may not include a contact portion RE-P. Similarly, one of thesecond electrodes 22_10 may include a contact portion RE-P, in which asecond contact hole CT2 is formed, and the other second electrode 22_10may not include a contact portion RE-P. Some of the electrodes (21_10and 22_10) electrically connected to a first transistor TR1 or a secondvoltage line VL2 may receive electrical signals via contact holes (CT1and CT2), and the other electrodes (21_10 and 22_10) may receiveelectrical signals via the contact electrodes (26_10, 27_10, and 28_10).

Both ends of each of the light-emitting elements 30 are disposed on theextended portions RE-E of the first electrodes 21_10 and the secondelectrodes 22_10, on the first insulating layer 51_10. First ends of thelight-emitting elements 30 where second semiconductor layers 32 aredisposed may be disposed on the first electrodes 21_10. Accordingly,first ends of first-type light-emitting elements 30-1, which aredisposed between leftward electrodes (21_10 and 22_10) that are disposedon the left side of the center of the first subpixel PX1, and first endsof second-type light-emitting elements 30-2, which are disposed betweenrightward electrodes (21_10 and 22_10) that are disposed on the rightside of the center of the first subpixel PX1, may face oppositedirections.

The display device 10 may include a relatively large number ofelectrodes (21_10 and 22_10) and may thus include a relatively largenumber of contact electrodes (26_10, 27_10, and 28_10).

The contact electrodes (26_10, 27_10, and 28_10) may include a firstcontact electrode 26_10, which is disposed on one of the firstelectrodes 21_10, a second contact electrode 27_10, which is disposed onone of the second electrodes 22_10, and a third contact electrode 28_10,which is disposed on the other first electrode 21_10 and the othersecond electrode 22_10 and surrounds the second contact electrode 27_10.

The first contact electrode 26_10 may be disposed on one of the firstelectrodes 21_10. For example, the first contact electrode 26_10 may bedisposed on the extended portion RE-E of the first electrode 21_10 wherethe first ends of the first-type light-emitting elements 30-1 aredisposed. The first contact electrode 26_10 may be in electrical contactwith the first ends of the first-type light-emitting elements 30-1 andwith the extended portion RE-E of the first electrode 21_10 where thefirst ends of the first-type light-emitting elements 30-1 are disposed.The second contact electrode 27_10 may be disposed on one of the secondelectrodes 22_10. For example, the second contact electrode 27_10 may bedisposed on the second electrode 22_10 where the first ends of thesecond-type light-emitting elements 30-2 are disposed. The secondcontact electrode 27_10 may be in electrical contact with the first endsof the second-type light-emitting elements 30-2 and with the secondelectrode 22_10 where the first ends of the second-type light-emittingelements 30-2 are disposed. The first and second contact electrodes26_10 and 27_10 may be in electrical contact with the electrodes (21_10and 22_10) where the first and second contact holes CT1 and CT2 areformed. The first contact electrode 26_10 may be in electrical contactwith the first electrode 21_10 electrically connected to the firsttransistor TR1, via the first contact hole CT1, and the second contactelectrode 27_10 may be in electrical contact with the second electrode22_10 electrically connected to the second voltage line VL2, via thesecond contact hole CT2. The first and second contact electrodes 26_10and 27_10 may transmit electrical signals applied thereto from the firsttransistor TR1 or the second voltage line VL2 to the light-emittingelements 30. The first and second contact electrodes 26_10 and 27_10 maybe substantially the same as their respective counterparts of any one ofFIGS. 2 through 33.

Electrodes (21_10 and 22_10) where the contact holes (CT1 and CT2) arenot formed may be further disposed in the first subpixel PX1. Theelectrodes (21_10 and 22_10) where the contact holes (CT1 and CT2) arenot formed may be in a floating state with substantially no electricalsignals applied directly thereto from the first transistor TR1 or thesecond voltage line VL2. The third contact electrode 28_10 may bedisposed on the electrodes (21_10 and 22_10) where the contact holes(CT1 and CT2) are not formed, and electrical signals transmitted to thelight-emitting elements 30 may flow via the third contact electrode28_10.

The third contact electrode 28_10 may be disposed on the electrodes(21_10 and 22_10) where the contact holes (CT1 and CT2) are not formedand may be disposed to surround the second contact electrode 27_10. Thethird contact electrode 28_10 may include portions that extend in thesecond direction DR2 and a portion that extends in the first directionDR1 to connect the portions that extend in the second direction DR2, andmay thus surround the second contact electrode 27_10. The portions ofthe third contact electrode 28_10 that extend in the second directionDR2 may be disposed on the electrodes (21_10 and 22_10) where thecontact holes (CT1 and CT2) are not formed, to be in electrical contactwith the light-emitting elements 30. For example, portion of the thirdcontact electrode 28_10 that is disposed on the second electrode 22_10where the second contact hole CT2 is not formed may be in electricalcontact with second ends of first light-emitting elements 30A, andportion of the third contact electrode 28_10 that is disposed on thefirst electrode 21_10 where the first contact hole CT1 is not formed maybe in electrical contact with first ends of second light-emittingelements 30B. The portion of the third contact electrode 28_10 thatextends in the first direction DR1 may overlap, but may not be directlyconnected to, the second electrode 22_10 where the second contact holeCT2 is formed, because of the presence of an insulating layer (notillustrated) therebetween.

Electrical signals transmitted from the first contact electrode 26_10 tothe first ends of the first-type light-emitting elements 30-1 may bedelivered to the third contact electrode 28_10, which is in electricalcontact with second ends of the first-type light-emitting elements 30-1.The third contact electrode 28_10 may transmit these electrical signalsto the first ends of the second light-emitting elements 30B so that thesignals may be transmitted to the second electrodes 22_10 via the secondcontact electrode 27_10. Accordingly, electrical signals for thelight-emitting elements 30 to emit light can be transmitted only to oneof the first electrodes 21_10 and the second electrode 22_10, and thefirst-type light-emitting elements 30-1 and the second-typelight-emitting elements 30-2 can be electrically connected in series viathe third contact electrode 28_10.

In concluding the detailed description, those skilled in the art willappreciate that many variations and modifications can be made to theembodiments without substantially departing from the principles of thedisclosure. Therefore, the disclosed embodiments of the disclosure areused in a generic and descriptive sense only and not for purposes oflimitation.

What is claimed is:
 1. A display device comprising: a plurality of firstbanks disposed on a substrate to extend in a first direction and spacedapart from one another; a plurality of first patterns disposed betweenthe plurality of first banks and spaced apart from one another in thefirst direction; a first electrode and a second electrode extending inthe first direction, disposed on different first banks of the pluralityof first banks, and spaced apart from each other; a first insulatinglayer overlapping the plurality of first patterns, disposed on thesubstrate, and partially overlapping the first and second electrodes;and a plurality of light-emitting elements disposed on the firstinsulating layer so that first and second ends of each of the pluralityof light-emitting elements are disposed on the first and secondelectrodes, respectively, the plurality of light-emitting elementsincluding first light-emitting elements which are disposed between theplurality of first patterns and do not overlap the plurality of firstpatterns in a thickness direction of the display device.
 2. The displaydevice of claim 1, wherein the plurality of light-emitting elementsfurther comprise second light-emitting elements which overlap theplurality of first patterns in the thickness direction of the displaydevice, and distances between the first light-emitting elements and thesubstrate are smaller than distances between the second light-emittingelements and the substrate.
 3. The display device of claim 1, wherein athickness of the plurality of first patterns is greater than thicknessesof the first and second electrodes.
 4. The display device of claim 3,wherein the thickness of the plurality of first patterns is smaller thana diameter of the plurality of light-emitting elements.
 5. The displaydevice of claim 1, wherein the plurality of first patterns are disposedbetween the first and second electrodes, and a width of the plurality offirst patterns is smaller than a distance between the first and secondelectrodes.
 6. The display device of claim 1, wherein a width of theplurality of first patterns is greater than a distance between the firstand second electrodes, and at least portions of the first and secondelectrodes are disposed on the plurality of first patterns.
 7. Thedisplay device of claim 1, further comprising: a planarization layerdisposed on the substrate, wherein the plurality of first banks and thefirst insulating layer are disposed on the planarization layer, and theplurality of first patterns and the planarization layer are integralwith each other.
 8. The display device of claim 1, wherein the pluralityof first patterns overlap portions of the first or second electrode thatdo not overlap the plurality of first banks and are arranged in thefirst direction.
 9. The display device of claim 8, wherein firstpatterns of the plurality of first patterns that overlap the firstelectrode and first patterns of the plurality of first patterns thatoverlap the second electrode are arranged parallel to a direction inwhich the first and second electrodes are spaced apart from each other.10. The display device of claim 8, wherein first patterns of theplurality of first patterns that overlap the first electrode and firstpatterns of the plurality of first patterns that overlap the secondelectrode are arranged in a staggered manner.
 11. The display device ofclaim 1, further comprising: a first contact electrode disposed on thefirst electrode to be in electrical contact with first ends of theplurality of light-emitting elements; and a second contact electrodedisposed on the second electrode to be in electrical contact with secondends of the plurality of light-emitting elements.
 12. The display deviceof claim 11, wherein the first electrode includes: at least one bentportion which extends in a second direction that is different from thefirst direction; an extended portion which has a greater width than theat least one bent portion; and at least one connecting portion whichelectrically connects the at least one bent portion and the extendedportion and extends in the first direction, and the plurality of firstpatterns are disposed between the extended portion of the firstelectrode and the second electrode.
 13. The display device of claim 12,wherein the second electrode is symmetrical with the first electrodewith respect to the first insulating layer, the plurality of firstpatterns are disposed between the extended portion of the firstelectrode and an extended portion of the second electrode, and a firstend and a second end of each of the plurality of light-emitting elementsare disposed on the extended portions of the first and secondelectrodes, respectively.
 14. The display device of claim 12, wherein afirst distance between the extended portion of the first electrode andthe second electrode is smaller than a second distance between the atleast one connecting portion of the first electrode and the secondelectrode, and a minimum distance between the at least one bent portionof the first electrode and the second electrode is greater than thefirst distance and is smaller than the second distance.
 15. A displaydevice comprising: a planarization layer disposed on the substrate; aplurality of first banks disposed on the planarization layer and spacedapart from one another; a first electrode and a second electrodedisposed on different first banks of the plurality of first banks andspaced apart from each other; a first insulating layer disposed on theplanarization layer and partially overlapping the first and secondelectrodes; first light-emitting elements disposed on the firstinsulating layer so that a first end and a second end of each of thefirst light-emitting elements are disposed on the first electrode andthe second electrode, respectively; and second light-emitting elementsdisposed on the first insulating layer so that a first end and a secondend of each of the second light-emitting elements are disposed on thefirst electrode and the second electrode, respectively, wherein adistance between the first light-emitting elements and the substrate issmaller than a distance between the second light-emitting elements andthe substrate.
 16. The display device of claim 15, wherein theplanarization layer includes first patterns including top surfacespartially protruding between the plurality of first banks, and thesecond light-emitting elements are disposed on the first patterns. 17.The display device of claim 16, wherein the planarization layer includesportions between the plurality of first banks where the first patternsare not formed, and the first light-emitting elements are disposed onthe portions of the planarization layer where the first patterns are notformed.
 18. The display device of claim 15, wherein the planarizationlayer includes recesses between the plurality of first banks where a topsurface of the planarization layer is recessed, at least portions of thefirst and second electrodes are disposed in the recesses, and the firstlight-emitting elements are disposed in the recesses.
 19. The displaydevice of claim 18, wherein the planarization layer includes portionsbetween the plurality of first banks where the recesses are not formed,and the second light-emitting elements are disposed on the portions ofthe planarization layer where the recesses are not formed.
 20. Thedisplay device of claim 15, further comprising: a transistor disposedbetween the substrate and the planarization layer; and a data conductivelayer disposed between the transistor and the planarization layer andincluding a first voltage line and a second voltage line, wherein thefirst electrode is electrically connected to the first voltage line viathe transistor, and the second electrode is electrically connected tothe second voltage line.